Important IELTS Grammar: The Structures That Actually Matter

An essay can contain relative clauses, conditionals and passive verbs yet remain difficult to follow. The problem may be a missing main clause, a comparison between unlike things or a small tense change that alters the timeline. Grammatical ambition does not compensate for losing control of the sentence.

The more useful question is what a structure allows you to express. A conditional separates a possibility from a certainty. A relative clause identifies which people you mean. A passive shifts attention from the person carrying out an action to what happens to the object. These are choices about meaning before they are evidence of range.

This guide concentrates on structures that recur in IELTS Writing and Speaking. It is a reference to return to while reviewing your own work, not a demand to fit every construction into one answer. All examples and numerical details are original teaching illustrations; they do not reproduce Cambridge tasks or describe actual research.

What “grammatical range” actually means

The official Writing descriptors assess the variety, flexibility and accuracy of structures, alongside control of punctuation. Strong performance requires language that serves the task. The descriptors do not prescribe a quota of conditionals, passive sentences or relative clauses.¹

Speaking assessment also considers how structures express the intended meanings, including clause patterns, verb phrases and the way information is organised. It recognises that spontaneous speech is not identical to edited prose. Natural ellipsis can be appropriate in conversation; an essay still requires control of written sentence boundaries.²

Range therefore includes choosing between a direct statement, an explanation, a qualification and a comparison. It can appear in a precise noun phrase as well as in a subordinate clause. Accuracy does not mean avoiding every difficult structure; it means developing enough control to use an appropriate variety reliably.

“Although the proposal would reduce journey times, its cost would limit spending elsewhere” contains a useful concession. Adding several further clauses merely to make it longer is unlikely to improve it. A short sentence can state the conclusion clearly: “That trade-off needs to be justified.”

Build a complete sentence before expanding it

Simple sentences

A simple sentence has one independent clause. “The rate fell” is simple. So is “The rate for younger workers fell sharply during the final three years.” Additional detail does not necessarily create another clause.

Look for the grammatical core: subject and finite verb. A finite verb carries the relevant tense or is part of a verb phrase with a finite auxiliary or modal. In “The figure has fallen”, has makes the verb phrase finite; fallen alone cannot normally carry that sentence.

Incorrect: “The number of applicants increasing every year.” Correct: “The number of applicants increases every year” or “The number of applicants is increasing.” The -ing form has been mistaken for a complete finite verb. Choose the correction that matches the intended meaning: a repeated pattern or a developing situation.

Simple does not mean unsophisticated. A clear statement of a key feature can be more effective than a long sentence whose subject becomes difficult to identify.

Compound sentences and coordination

A compound sentence coordinates independent clauses: “Demand increased, but capacity remained unchanged.” Both clauses can stand alone. The conjunction identifies the relationship between them. And adds; but contrasts; so introduces a result.

Do not assume every sentence containing and is compound. “The council repaired and reopened the library” coordinates verbs within one clause. The useful skill is recognising what has been joined, not collecting labels.

Incorrect: “Demand increased, capacity remained unchanged.” Correct: “Demand increased, but capacity remained unchanged.” A full stop or semicolon could also separate these independent clauses. The mistake is using a comma alone to do work it cannot normally do in formal prose.³

Complex sentences and subordination

A complex sentence contains an independent clause and at least one subordinate clause: “Although demand increased, capacity remained unchanged.” The subordinate clause establishes the condition, reason, contrast or other background against which the main statement should be understood.

Incorrect as a complete written sentence: “Although the service is expensive.” Correct: “Although the service is expensive, it remains popular.” The initial clause creates an expectation that has not been fulfilled. It may be natural to leave things unspoken in some conversation, but this is a fragment in an essay paragraph.

Begin by deciding which idea deserves main-clause status. “The project was delayed because funding was unavailable” centres the delay. “Because funding was unavailable, the project was delayed” foregrounds the reason. Neither order is automatically a higher-band choice.

Relative clauses: identify precisely, then add detail

Defining relative clauses

A defining clause identifies the person or thing being discussed. “Students who work at night may need flexible timetables” concerns the students who work at night, not necessarily every student. Do not insert commas if that restriction is intended.

Use who for people, which for things and, in defining clauses, that for either where appropriate. Whose expresses a possessive relationship. Where is useful when the clause needs a place expression: “the town where I studied”.⁴

Incorrect: “Students who they work at night need flexibility.” Correct: “Students who work at night need flexibility.” Who is already the subject of the relative clause; they duplicates that role.

When the relative pronoun is the object, it can often be omitted: “The course that I chose” becomes “The course I chose”. When it is the subject, it cannot normally disappear in the same way: “The course that starts on Monday” cannot become “The course starts on Monday” while remaining the same noun phrase. The latter is a complete statement instead.

Non-defining relative clauses

A non-defining clause supplies additional information about something already identified: “The central library, which reopened in June, now closes later.” Commas mark that additional material. Use which rather than that for a thing, and keep the relative pronoun.⁵

Incorrect: “The central library, that reopened in June, now closes later.” Correct: “The central library, which reopened in June, now closes later.” The error comes from applying the defining-clause options to a different construction.

The punctuation can change the claim. “The buses that are electric are quieter” singles out the electric buses. “The buses, which are electric, are quieter” presents the buses under discussion as electric. Choose according to the information you actually have.

Avoid detached or misleading descriptions

Keep the relative clause close to its intended noun. “The council discussed the proposal with residents, which was expensive” leaves the reader uncertain about what was expensive: the proposal or the discussion. Write “The council discussed the expensive proposal with residents” if that is the intended meaning.

Which can also refer to a whole preceding idea: “The last bus leaves early, which makes evening work difficult.” That is legitimate, but the reference must remain clear. A relative clause is useful only when the reader can connect it to the right information.

Adverbial clauses: show the relationship between ideas

Although and even though

Although introduces a concession: something remains true despite a potentially contrary consideration. “Although the new route is shorter, it is not faster.” Even though makes that contrast more emphatic.

Incorrect: “Although the route is shorter, but it is not faster.” Correct: “Although the route is shorter, it is not faster” or “The route is shorter, but it is not faster.” The learner has combined two alternative ways of organising the contrast.

Although takes a clause. Despite takes a noun phrase or an -ing construction: “despite the shorter route”; “despite travelling a shorter distance”. “Despite the route is shorter” does not have the intended structure. “Despite the fact that the route is shorter” is possible, but the simpler although version is often sufficient.

Because, since and because of

Because gives a reason explicitly: “Some students work because they need an income.” Since can also introduce a reason, but has a time meaning as well. If the reader might interpret it as from a particular time onwards, because can remove the ambiguity.

Incorrect: “The service was cancelled because low demand.” Correct: “The service was cancelled because demand was low” or “The service was cancelled because of low demand.” Because introduces a clause; because of introduces a noun phrase.

Do not add a causal connection simply because the grammar permits one. In Task 1, a higher fee and lower attendance may be visible, while the cause of the attendance change is not. Grammatical correctness does not make an unsupported explanation accurate.

While and whereas

While can express time or contrast: “I listened while I walked” concerns simultaneous activities; “Bus use fell while rail use rose” contrasts trends. Whereas is a useful alternative when you want the contrast to be unmistakable.

Incorrect: “Whereas rail use rose.” Correct: “Bus use fell, whereas rail use rose.” The contrasting clause has been left without the statement it contrasts with. These words connect ideas; they do not replace the need for a complete sentence.

Noun clauses: make an idea the subject or object

A noun clause allows a whole proposition or question to occupy a grammatical role often occupied by a noun phrase. In “The report suggests that demand will fall”, the that-clause supplies what the report suggests. In “Whether the scheme is affordable remains uncertain”, the whether-clause is the subject.

“It is clear that the two groups followed different patterns” places the claim after an introductory it. The fact that can introduce a situation you then discuss: “The fact that a service is popular does not establish that it is affordable.” What matters is focuses attention: “What matters is whether the system reaches those who need it.”

Use these constructions because they organise the meaning, not because they look academic. “It is clear that” should not disguise a claim that is actually uncertain. Often “The two groups followed different patterns” is enough.

Incorrect: “The question is whether can the policy work.” Correct: “The question is whether the policy can work.” An embedded question normally uses statement word order, rather than the inversion found in the direct question “Can the policy work?”

Incorrect: “The fact that the cost is high.” Correct: “The fact that the cost is high does not make the proposal unreasonable.” A long subject is still only a subject until the sentence supplies its main predicate.

Conditionals: separate real possibilities from imagined ones

General relationships and possible futures

For a general relationship, a present-tense pattern is useful: “If a device has no power, it does not operate.” For a future possibility, use a present form in the ordinary if-clause with an appropriate future result: “If the timetable changes, some passengers will need another route.”⁶

The result need not contain will. “If demand grows, the council may extend the service” expresses a possible response; “If you need clarification, ask the examiner” is an instruction. These are meaningful choices, not exceptions to memorise reluctantly.

Incorrect for an ordinary future condition: “If the timetable will change, commuters will need another route.” Correct: “If the timetable changes, commuters will need another route.” Will is not normally required in that if-clause merely because the situation is future. Special uses expressing willingness exist, so avoid claiming that will can never follow if.

Hypothetical situations

“If fares were lower, I would use the train more often” imagines a different present or future situation. The past form marks distance from reality here, not past time. It is useful for considering a policy or explaining a preference in Speaking.

For an unreal past alternative: “If the repair had started earlier, the bridge would have reopened before winter.” The pattern is had plus past participle in the condition and would have plus past participle in the result.

Incorrect: “If the repair had started earlier, the bridge would reopen before last winter.” Correct: “If the repair had started earlier, the bridge would have reopened before last winter.” The result needs to match the intended past counterfactual. Mixed conditionals are possible when the time relationship is genuinely mixed; they are not a remedy for accidental inconsistency.

Do not force a conditional into a Task 1 report of completed figures. It may speculate about information the task does not provide. Use it when considering possibilities is actually part of the answer.

Passive voice: choose the focus, not the formality

The passive typically uses an appropriate form of be plus a past participle: “The samples are tested”; “The bridge was repaired”; “The results have been checked.” It foregrounds the thing affected. The agent can be added with by when useful, but need not be repeated when obvious or irrelevant.⁷

This is particularly useful in a manufacturing process: “The mixture is heated and then filtered.” The materials and stages, rather than an unnamed worker, carry the description forward. In a historical description, the tense changes: “The warehouse was converted into a museum.”

Incorrect: “The mixture heated before it is filtered.” Correct for the intended passive process: “The mixture is heated before it is filtered.” The auxiliary has been omitted. “The mixture heated” could be active past-tense language in another context, but it does not express this present passive process.

Potentially misleading: “The number was increased from 30 to 40” when no agent or deliberate intervention is intended. Prefer “The number increased from 30 to 40.” The passive is possible when someone did increase it; it should not be added mechanically to every trend verb. “The number was risen” is not a grammatical passive of rise.

Passives are not inherently more academic than active sentences. “The council rejected the proposal” is clearer when the responsible institution matters. Removing the agent can conceal information the argument needs.

Comparatives: compare like with like

Basic and modified comparisons

Use higher than, lower than, more expensive than and less accessible than. Modify a comparative with much, considerably, substantially, slightly or marginally: “The second figure was considerably higher.” Do not use very directly before a comparative in the same way.

Incorrect: “The second figure was more higher.” Correct: “The second figure was higher.” Higher already marks the comparison. “Much higher” intensifies it without duplicating the comparative form.

Incorrect: “Spending in City A was higher than City B.” Correct: “Spending in City A was higher than spending in City B” or “higher than that in City B”. The comparison needs two amounts of spending, not an amount and a city.

Multiples and ordered pairs

“The library had twice as many visitors as the gallery” compares countable visitors. “The factory used three times as much water as the workshop” compares an uncountable quantity. “Three times the amount of water” is another clear construction.

Incorrect for the intended meaning of exactly triple: “The factory used three times more water.” Prefer “three times as much water”. Times more can produce ambiguity about whether the additional amount or the total is being compared. A reference article should favour the unambiguous version.

Respectively connects items in order: “The figures for cars and buses were 80 and 20, respectively.” It is an adverb, not a comparison structure by itself. If the order is unclear, writing two short clauses is better than making the reader solve a matching exercise.

Compared with

“Compared with the earlier figure, the later figure was higher” makes the two measures explicit. Avoid a dangling comparison such as “Compared with the earlier figure, there were more passengers” when it leaves the compared element uncertain. “Passenger numbers were higher than in the previous year” is often cleaner.

Use the comparison to reveal the key feature. Grammar should help you state whether the difference concerns a number, proportion, rate, total or average. These are not interchangeable units.

Articles: small words that organise reference

A and an

A singular count noun usually needs a determiner in an ordinary noun phrase. When introducing one nonspecific example, use a or an: a policy, an argument. A possessive or another determiner can fill that role instead: my argument, this policy.

Choose a or an by sound, not merely the written first letter: a university, an hour. The initial sound of university is /j/; hour begins with a vowel sound. An adjective can change the choice because the next sound changes: a report, an accurate report.⁸

Incorrect: “Government should provide solution.” Correct: “The government should provide a solution” in a discussion of a particular government. If speaking generally, “Governments should provide solutions” may be intended. The missing determiners cannot be repaired properly without identifying the meaning.

The

The normally helps identify the particular thing or group intended: “A survey was conducted. The survey covered three districts.” It can also identify something made specific by its description: “the number of households in the sample”. Prior mention is useful, but not the only reason to use the.⁹

Incorrect for a general claim: “The education is important.” Correct: “Education is important.” But “The education provided by this programme is practical” refers to a defined form of education. The presence of extra words alone does not demand the; what matters is how the noun is being identified.

Zero article

General plural and uncountable nouns often take no article: “Students need feedback”; “Research requires careful planning.” The article can change the scope: “The students need feedback” refers to an identifiable group.

Incorrect: “The technology improves the communication” when making a broad statement about technology and communication. Usually: “Technology improves communication.” A specific context might justify either the, so the repair depends on reference, not a universal ban on articles before abstract nouns.

Learn recurring expressions such as at university, in society and access to education in context. Do not try to assign an article mechanically to every noun based on its translation into another language.

Countable and uncountable nouns

Information, advice, evidence, equipment and traffic are normally uncountable in the uses most relevant here. Use some information, a piece of advice, a body of evidence, an item of equipment and a large amount of traffic. Their ordinary mass uses do not take a plural -s.¹⁰

Incorrect: “These informations are useful.” Correct: “This information is useful” or “These details are useful.” The problem involves both the noun and its agreement. Removing the final s without changing these and are leaves the sentence incorrect.

Research is usually uncountable when it names investigation: “Research has identified several possibilities.” Individual projects can be called studies. Do not write “a research” when you mean a study. Work is uncountable for activity or employment, while jobs are countable. A work of literature is a different, countable sense of work.

Countability belongs to a meaning, not always permanently to an entire word. Experience can mean accumulated knowledge or a particular event: “She has relevant experience”; “It was a memorable experience.” In Speaking, choosing the wrong pattern may change what the listener understands.

Subject–verb agreement: find the head of the subject

The finite verb normally agrees with the grammatical subject, not the nearest noun. “The number of applications has increased.” The head is number, which is singular; applications is inside a modifying phrase.

Contrast “A number of applicants have withdrawn”, where a number of functions as a plural quantity expression. The similarity of the two phrases can conceal the different agreement patterns. Likewise, “The quality of the answers varies” needs varies, not vary.

Incorrect: “One of the reasons are cost.” Correct: “One of the reasons is cost.” One is the singular head. “The reasons are cost and distance” has a plural subject and therefore a plural verb.

With percentages, agreement often follows what is being measured: “Thirty per cent of the water is lost”; “Thirty per cent of the respondents are dissatisfied.” Collective nouns can allow variation depending on dialect and whether the group is viewed as a unit or as individuals. Avoid teaching every legitimate variation as an error.

When checking your own writing, temporarily remove the words between the subject and verb. “The availability of affordable homes near the new station has improved” becomes “The availability has improved.” That makes the agreement easier to hear.

Tense control: establish the timeline

Historical data

Use the past simple for completed past periods: “The rate fell between 2005 and 2015.” The reporting verb can remain present: “The chart shows that the rate fell.” The chart is in front of the reader; the event belongs to the past.

Incorrect: “The figure has risen in 2012.” Correct for a completed event in that year: “The figure rose in 2012.” The present perfect does not normally combine with that finished past-time reference. If the intended period extends to now, a sentence such as “The figure has risen since 2012” makes a different claim.

Current situations and continuing developments

The present simple can describe a current state or recurring pattern: “The service operates every day.” The present continuous can describe an ongoing change: “The service is expanding.” Choose according to the situation rather than treating all present-time statements alike.

Incorrect for an ordinary statement of understanding: “I am knowing how the system works.” Correct: “I know how the system works.” Know is normally a state verb in this meaning. Other verbs can be either states or activities depending on their sense: “I think it is useful”; “I am thinking about the problem.”

Predictions and projections

Use wording that preserves the difference between an observed value and a forecast: “Demand is projected to reach 80 units by 2030.” Will can express a prediction, but projected, forecast or expected makes the status of supplied figures especially clear.

Incorrect when describing a projection: “Demand reached 80 units in 2030” if that year lies in the future of the task's timeframe. The problem is not only the verb form; it turns a projected outcome into an observed event. Always establish the dates before drafting.

Processes

A general process normally uses the present simple: “Water enters the chamber”; “The material is cooled.” A description of a completed experiment or a historical process may need the past instead. Process language is not automatically passive: “The water evaporates” is a natural active sentence.

Meaning changes with the construction: “The water is evaporated and then flows” is grammatical, but presents the first stage as an externally caused action. Choose “evaporates” if the diagram simply presents what the water does. Voice and tense should reflect the process, not a memorised rule about diagrams.

Modal verbs: ability, possibility, advice and necessity

Modal verbs such as can, could, may, might, should and must normally take a base-form verb without to: “may reduce”, “could improve”, “must remain”. They do not take third-person -s. “It may reduces costs” becomes “It may reduce costs.”

Can often expresses ability or general possibility: “Digital access can remove a geographical barrier.” May and might often express a possibility in a particular situation. Could can express ability in the past, a hypothetical option or a possibility, depending on context. Do not assign each modal one fixed meaning or a permanent probability percentage.

Should often recommends a course of action: “The council should publish the criteria.” Must can express a strong obligation: “Applicants must provide identification.” It can also express a strong inference: “The office is dark; it must be closed.” The second meaning is not an instruction to close it.

Incorrect if no certainty is justified: “Online learning must improve every student's results.” A more defensible claim might be “Online learning may help students who need flexible access.” This revision changes the scope as well as the modal. Hedging cannot rescue a claim that remains implausibly broad.

Hedging: qualify the claim, not every word

Hedging signals the limits of a statement. May marks possibility; tends to describes a general tendency with potential exceptions; appears to distinguishes an impression or inference from a fully established fact; is likely to expresses an expectation.

“Long journeys tend to discourage participation” leaves room for exceptions. “The change appears to have improved access” indicates an inference. “Poor lighting can contribute to fatigue” identifies a possible contributing factor rather than a complete causal account.

Incorrect: “The policy may can improve access.” Correct: “The policy may improve access” or “The policy can improve access”, according to the intended meaning. Standard English does not ordinarily stack these two modal auxiliaries in one verb phrase.

Avoid weakening every clause indiscriminately: “It may perhaps possibly be the case” rarely adds useful precision. State a directly observed value plainly. Qualify an inference where the evidence, scope or circumstances require it. This makes an argument more accountable, not merely more cautious-sounding.

Cohesion through grammar

Reference and pronouns

Pronouns and demonstratives connect sentences without repeating everything: “The service is infrequent. This limits its usefulness.” But this can be too vague if several previous ideas compete as its reference. “This infrequency limits the service's usefulness” names the link more clearly.

Unclear: “The council discussed the complaints with the operators, and they rejected the proposal.” Who rejected it? Clearer: “The operators rejected the proposal after discussing the complaints with the council.” Grammar can be structurally possible while reference remains ambiguous.

Use singular or plural references consistently: “The policy has a drawback. It is expensive”; “The policies have drawbacks. They are expensive.” The subject matter may involve many people, but it still refers to a singular policy in the first example.

Substitution and controlled repetition

“The first method is expensive; the second is less so” substitutes so for expensive. “Some respondents preferred the bus; others did not” avoids repeating preferred the bus. These choices can make prose efficient when the missing meaning is clear.

Incorrect for an uncountable reference: “The equipment in this room is newer than the ones next door.” Correct: “The equipment in this room is newer than that next door.” Ones normally replaces plural countable things, not the uncountable equipment.

Substitution should not become a puzzle. Repeat the key noun if that makes the comparison easier to follow. Likewise, however and therefore should name real logical relationships. Adding therefore does not make a conclusion follow from the previous sentence.

Parallel structures

Parallelism gives coordinated items a compatible grammatical shape: “The programme aims to improve access, reduce delays and simplify applications.” The verbs describe three corresponding aims.

Incorrect: “The programme aims to improve access, reducing delays and the simplification of applications.” Correct: “The programme aims to improve access, reduce delays and simplify applications.” The original mixes an infinitive, an -ing form and a noun phrase without a clear structure.

Another option is a noun-based list: “The aims are improved access, shorter delays and simpler applications.” Parallelism is not a prohibition on all grammatical variation. It helps the reader recognise items that have the same logical role.

Keep paired constructions balanced: “The policy affects not only employees but also employers.” In “The policy not only affects employees but also the employers”, the reader may expect a second verb phrase. Place the paired markers around genuinely corresponding elements.

Gerunds and infinitives

The form after a verb often belongs to that verb's pattern. Enjoy, avoid and consider commonly take an -ing form: enjoy reading, avoid repeating, consider moving. Decide, hope and plan commonly take a to-infinitive: decide to apply, hope to improve, plan to relocate.

Incorrect: “Students should avoid to memorise entire essays.” Correct: “Students should avoid memorising entire essays.” The infinitive has been transferred from the pattern of a different verb. In “Students should try to understand the argument”, try to is appropriate for making an attempt.

Sometimes the choice changes the meaning. “I stopped checking my phone” means I no longer continued that activity. “I stopped to check my phone” means I interrupted another activity for that purpose. “I remember sending the email” concerns a memory; “I remembered to send the email” means I did not forget to perform the action.

An -ing clause can act as a subject: “Reading regularly helps me notice useful patterns.” Its verb is singular because the activity is treated as one subject. “Reading regularly help” is an agreement error, even though the reading involves many texts.

After a preposition, an -ing form is common: interested in learning, responsible for maintaining, an approach to solving a problem. To is not always an infinitive marker. Compare “I hope to learn” with “I look forward to learning”.

Prepositions: learn the whole relationship

Prepositions connect meanings and form established patterns: depend on, benefit from, access to, a reason for, a solution to, an effect on, interested in and responsible for. Learning the main word without its pattern leaves an important part of the sentence unfinished.

Incorrect: “The result depends of the sample.” Correct: “The result depends on the sample.” The problem often comes from translating a preposition independently from another language. English does not distribute these relationships identically.

Avoid adding a preposition where the verb takes a direct object: discuss the question, approach the problem, describe the process. Contrast the related nouns: a discussion about the question, an approach to the problem, a description of the process.

For change, distinguish from, to, by and at: “The figure rose from 30 to 45, an increase of 15, and then remained at 45.” For periods, distinguish since a starting point from for a duration: since 2020, for six years. These small words determine the actual numerical or temporal claim.

Punctuation and sentence boundaries

Commas

Commas can separate an introductory subordinate clause from the main clause, mark non-defining information and organise a list. They do not simply mark every place where you might pause while speaking.

Incorrect: “The main reason for the delay, was a shortage of staff.” Correct: “The main reason for the delay was a shortage of staff.” Do not separate the ordinary subject from its verb with a comma. A pair of commas can enclose inserted information, but a single misplaced comma cannot perform that job.

“Although the cost increased, demand remained stable” uses a comma after an opening subordinate clause. With “Demand remained stable because the cost increase was small”, no comma is normally needed before the closely connected reason. Punctuation depends on the construction, not a rule that every long sentence needs a comma in its middle.

Semicolons and colons

A semicolon can join closely related independent clauses: “The first route is shorter; the second is cheaper.” It is optional; two full stops may be equally clear. It does not make the vocabulary or argument more advanced by itself.

Incorrect: “The first route is shorter; because it avoids the centre.” Correct: “The first route is shorter because it avoids the centre.” The material after the semicolon is a dependent reason clause, not the independent clause this construction requires.

A colon can introduce an explanation or list after a complete clause: “The proposal has two weaknesses: cost and limited coverage.” Avoid separating a verb directly from its complement: “The weaknesses are: cost and limited coverage” is better written without that colon in ordinary continuous prose.

Run-on sentences and fragments

Incorrect: “Fares increased passengers changed routes.” Correct: “Fares increased, so some passengers changed routes” if that causal connection is intended and supported. A full stop can instead keep the observations separate. A run-on is a boundary problem, not simply any sentence that happens to be long.

Incorrect as a standalone essay sentence: “Which makes the scheme difficult to justify.” Correct: attach it to the relevant clause, or write “This makes the scheme difficult to justify.” The reader needs both the reference and the complete written sentence.

In Speaking, pauses, intonation and context can make short responses natural. “Probably next year” may answer a conversational question effectively. Do not use that fact to justify broken sentence boundaries in Writing, or use essay punctuation as a reason to make conversation unnaturally elaborate.

Grammar mistakes that commonly prevent higher bands

Persistent agreement errors, missing articles and unstable verb forms can affect a response even when the argument is strong. Other problems are less visible: a relative clause that changes the group being discussed, a tense that turns a prediction into a fact or a pronoun whose reference is uncertain.

The published descriptors consider the pattern and impact of errors alongside the range of structures used. There is no universal conversion such as “three mistakes equals Band 6”. Nor does including one flawless complex sentence establish control across the response.¹

When reviewing a script, separate an occasional slip from a recurring gap. If every uncountable noun is pluralised, the problem is a system to learn. If a usually accurate form fails once, the next step may be checking under time pressure. The correction process should reflect the kind of error.

Do not respond to mistakes by retreating permanently into only short sentences. Rebuild difficult constructions in manageable steps. First write the complete main clause; then add the reason, contrast or qualification. Check that the original sentence core still works.

A review method that develops control

Read once for meaning: can another person identify the claim, the evidence and their relationship? Then check sentence boundaries. Mark the finite verbs and their subjects in any sentence that feels unstable. A sentence with many impressive nouns but no main verb is still unfinished.

On another pass, check the timeline, countability, articles and agreement. Compare like with like in every data statement. Circle pronouns whose reference is unclear. Review the patterns after verbs and prepositions. This focused sequence is usually more actionable than telling yourself to “check grammar”.

For Speaking, record a short answer and transcribe a manageable section. Keep the natural features of speech, but identify patterns that repeatedly blur the message. Correct the passage, then answer the same question again without reading the correction aloud. The purpose is to make the pattern available while thinking about meaning.

Keep a small personal error record containing the original sentence, a correction, the explanation and a new example. Return to the pattern in a different topic. Accuracy that survives a change of subject is more useful than a perfectly memorised sentence about one familiar question.

The aim is not to sound as though you are demonstrating grammar. It is to control time, reference, comparison and qualification so well that the reader or listener can concentrate on what you mean. That is what makes grammatical range worth developing.

For the meanings and collocations that work with these structures, read Important IELTS Vocabulary: What You Actually Need to Know.