IELTS Reading question type

IELTS Reading Sentence Completion: Complete Strategy Guide

Learn exactly how to recognise this question type, manage time, avoid the common traps and practise with original example questions and full explanations.

Step-by-step methodWorked examplesTimed practiceBand-focused advice

What Is Sentence Completion?

IELTS Sentence Completion requires you to complete a sentence using words taken directly from the passage. The word limit always appears in the instructions, often as NO MORE THAN TWO WORDS AND/OR A NUMBER, and that limit must be respected exactly. You must use the exact words from the passage rather than paraphrasing, and the finished sentence must remain grammatically correct. This question type usually appears in sets of four to six items and can show up in any passage. In many tests, the answers follow the order of the passage, which helps you track your place efficiently. The single most important strategy is to use grammar clues before you search. If the gap clearly needs a noun, verb, adjective or number, you can reject many wrong possibilities before you even locate the relevant lines.

For the wider test structure, read the IELTS Reading Guide or return to the Question Types hub.

How to Identify This Question Type

Instruction keywords

  • Complete the sentences below
  • Write NO MORE THAN TWO WORDS AND/OR A NUMBER
  • ONE WORD ONLY

Answer sheet

You copy the exact word or phrase into the answer space. The wording must fit the instruction exactly, including any number limit.

Typical count

Usually 4-6 items in one set, often arranged in passage order.

Typical passage

Can appear in Passage 1, 2 or 3 and in both IELTS Reading formats. It is especially common in factual or process-based passages.

Time allocation

About 90 seconds per question, or 6-8 minutes for a five-question set.

Step-by-Step Strategy

  1. 1

    Read the word limit instruction carefully

    Check whether the task allows one word, two words or a number. A correct idea written with too many words still receives no mark.

  2. 2

    Read the incomplete sentence and identify the word type needed

    Use grammar to predict whether the gap needs a noun, verb, adjective, number or short phrase. This narrows your search and reduces guesswork.

  3. 3

    Identify keywords in the sentence stem

    Find the stable words that will help you locate the right section in the passage. These may be names, processes, materials, places or dates.

  4. 4

    Locate the relevant section in the passage

    Scan for the keywords or their close synonyms and read the nearby lines carefully. Sentence completion answers normally come from a tight group of lines, not the whole passage.

  5. 5

    Find the exact words from the passage

    Your answer should normally be copied directly from the text. Do not improve it, shorten it or switch it into a different grammatical form unless the passage already uses that form.

  6. 6

    Check that the completed sentence makes grammatical sense

    Read the whole sentence aloud in your head. If the grammar breaks, you may have copied too much, too little or the wrong form of the phrase.

  7. 7

    Check the word count one final time

    Count each word carefully and remember that articles such as a or the count as words. Never exceed the limit, even by one word.

Most important step

Use the grammar of the sentence stem before you search the passage. Knowing you need a noun, number or adjective makes the right answer much easier to spot and the wrong answers easier to reject.

The Grammar Clue Strategy

The sentence stem often tells you what type of word you need before you find the answer.

Noun clue

"The experiment was conducted in a ___" tells you the gap needs a place or container noun.

Adjective clue

"Researchers found the results were ___" signals an adjective describing the results.

Verb clue

"The process begins when scientists ___" tells you the gap needs a verb phrase.

Word Limit Rules

Sentence completion is unforgiving about instructions, so the limit matters as much as the meaning.

NO MORE THAN TWO WORDS

You may write one word or two words, but never three. A three-word answer is automatically wrong.

NO MORE THAN TWO WORDS AND/OR A NUMBER

You may include a number such as 45 minutes or 3 stages, provided the total still respects the instruction.

ONE WORD ONLY

You must write exactly one word. Hyphenated words count as one word, but articles such as a and the still count as words if they are separate.

Do not paraphrase. If the passage says coastal waters, you cannot turn that into marine waters.

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Common Mistakes

Exceeding the word limit

Why it costs marks: This is an automatic zero even if the meaning is correct. Students often copy the whole phrase they see without checking whether a shorter extract would fit.

Exact fix: Count the words after you choose the answer and trim only if the trimmed version is still an exact phrase from the passage.

Incorrect Approach

Incorrect approach: Writing 'the coastal reef system' when the instruction is NO MORE THAN TWO WORDS.

Correct Approach

Correct approach: Writing 'reef system' if that exact two-word phrase appears in the passage and still completes the sentence correctly.

Paraphrasing instead of using exact passage words

Why it costs marks: Sentence completion normally requires direct copying from the passage. A neat paraphrase may sound intelligent, but it is still the wrong format for the task.

Exact fix: Find the exact word or phrase in the text and lift it without rewriting. The task is testing accurate retrieval, not free expression.

Incorrect Approach

Incorrect approach: Changing 'coral bleaching' to 'reef whitening' because it sounds similar.

Correct Approach

Correct approach: Copying 'coral bleaching' exactly because that is the wording used in the passage.

Ignoring grammatical fit

Why it costs marks: A copied phrase can still be wrong if it does not fit the sentence structure. Students sometimes copy a plural noun where the sentence clearly needs a singular one.

Exact fix: Read the full completed sentence after writing the answer. If the grammar sounds broken, recheck the passage and the stem.

Missing articles or prepositions in the count

Why it costs marks: Small words affect both grammar and word count. Leaving them out or adding them when they are not part of the copied phrase changes the validity of the answer.

Exact fix: Treat articles and prepositions seriously. Count them when they are part of the copied phrase, but do not invent them if the passage does not give them.

Copying too many words from the passage

Why it costs marks: Students often take a long chunk because it feels safe, but long chunks usually break the instruction or the sentence grammar.

Exact fix: Aim for the smallest exact phrase that completes the sentence correctly. More words usually means more risk, not more security.

For wider exam technique, read Common IELTS Mistakes and How to Use IELTS Practice Tests.

Practice: Sentence Completion Questions

Read the passage on coral reef conservation and complete the sentences using words from the passage.

Protecting Coral Reefs

Coral reefs support enormous marine biodiversity, yet many reef systems are under pressure from warmer seas, pollution and destructive fishing methods. Marine scientists have found that coral bleaching becomes more likely when water temperatures stay unusually high for extended periods. In response, several conservation groups now focus on early-warning monitoring rather than waiting for visible reef damage.

Some projects also work with local fishing communities to reduce harmful practices near fragile reef zones. These schemes are most effective when they combine scientific data with practical education, because residents are more likely to change behaviour when they understand how reef decline affects future fish stocks and coastal tourism. Long-term protection therefore depends on both environmental monitoring and community cooperation.

Instructions

Questions 1-5: Complete the sentences below. Write NO MORE THAN TWO WORDS AND/OR A NUMBER for each answer.

1

Coral bleaching is more likely when water temperatures remain high for extended ______.

2

Some conservation groups prioritise ______ monitoring before obvious reef damage appears.

3

Projects often work with local ______ communities to reduce harmful practices.

4

Education is important because it helps residents understand the effect on future fish stocks and ______.

5

Long-term reef protection depends on environmental monitoring and community ______.

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How Much Time to Spend on Sentence Completion

  • Sentence Completion usually takes around 90 seconds per item, so a five-question set should stay near 7-8 minutes.
  • If the answer is not obvious after a minute, move on rather than forcing a phrase that may break the word limit.
  • Because answers often follow passage order, use each completed item to guide your search for the next one.
  • In the overall 60-minute strategy, this task rewards clean instruction-checking and grammar awareness more than speed-reading bravado.

Frequently Asked Questions

Do I have to use exact words from the passage for sentence completion?

Yes, in standard IELTS Reading sentence completion tasks you are normally expected to use exact words from the passage. The wording must be copied accurately and must fit the word limit. Paraphrasing is usually not accepted because the task tests precise retrieval.

What happens if I exceed the word limit?

If you exceed the word limit, the answer is marked wrong even if the idea is correct. IELTS applies the instruction strictly, so one extra word can cost you the mark. That is why a final word-count check is essential.

Do hyphenated words count as one or two words?

Hyphenated words count as one word in IELTS. For example, early-warning is one word, not two. This matters when you are close to the instruction limit.

Do sentence completion questions follow the order of the passage?

Usually, yes. The answers often appear in the same order as the questions, which helps you track your position in the text. Even so, you should still verify each answer in the local lines rather than relying on order alone.

Can I change the form of the word for sentence completion?

In most IELTS Reading sentence completion tasks, no. You should copy the exact form used in the passage unless the task specifically allows another form, which is unusual. Changing a noun to a verb or singular to plural often makes the answer invalid.

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For deeper preparation, read the IELTS Preparation Guide, the India preparation guide, How to Use IELTS Practice Tests and Common IELTS Mistakes.