IELTS Reading Sentence Completion: Strategy & Practice Guide

Sentence completion is one of the most common question types in the IELTS Reading test. It appears in nearly every exam and requires you to complete a sentence using words taken directly from the reading passage. While it may seem straightforward, many candidates lose marks through careless mistakes — exceeding word limits, choosing the wrong form of a word, or missing the answer because they searched for exact phrases instead of paraphrases.

This guide will give you a systematic strategy for approaching sentence completion questions, along with practical techniques to maximise your accuracy.

Understanding the Question Format

Sentence completion questions look like this:

Complete the sentences below. Choose NO MORE THAN TWO WORDS from the passage for each answer.

1. The researchers discovered that the main cause of the decline was __________.
2. The new policy was introduced in __________ to address growing concerns.

Key features to note:

• The instructions specify a word limit (usually one, two, or three words)
• Answers must come directly from the passage — you cannot paraphrase
• The sentences generally follow the order of the passage
• The sentences use synonyms and paraphrases of the original text

Step-by-Step Strategy

Step 1: Read the Instructions Carefully

Before you look at any sentences, check the word limit. This will constrain your answers and help you predict what type of word you need.

Step 2: Read the Incomplete Sentence

Read each sentence and identify:

• What type of word is missing — Is it a noun, verb, adjective, or adverb? The grammar of the sentence tells you.
• What topic area the sentence covers — This helps you locate the relevant section in the passage.
• Key words that will help you scan — Underline distinctive words (names, dates, technical terms) that you can search for.

Step 3: Predict Before You Search

Before looking at the passage, try to predict what the answer might be. You will not guess the exact word, but you can predict the type of information needed.

Example: "The experiment was conducted in a controlled __________."

Prediction: a noun, probably a type of space or location (environment, laboratory, setting)

Step 4: Scan the Passage

Use the key words from the sentence to scan the relevant section of the passage. Remember that the sentences usually follow the order of the passage, so if you found the answer to question 1 in paragraph 2, question 2 will probably be in paragraph 2 or later.

Step 5: Read the Surrounding Context

Once you locate the relevant section, read two to three sentences around it carefully. The answer is rarely in the exact sentence that contains your scanning keyword — it is often in the sentence before or after.

Step 6: Choose Your Answer and Check

Select the word(s) from the passage that complete the sentence. Then check:

• Does it fit grammatically?
• Does it make logical sense?
• Does it respect the word limit?
• Is it spelled exactly as in the passage?

Grammar-Based Elimination

The grammar of the incomplete sentence is one of your most powerful tools. Use it to determine what type of word is needed:

After an Article (a, an, the)

You need a noun or adjective + noun.

• "The researchers used a new __________." → noun expected

After a Preposition (in, on, at, by, with)

You need a noun or noun phrase.

• "The species was found in __________." → noun (a place or environment)

Before a Noun

You need an adjective or noun modifier.

• "The __________ approach was more effective." → adjective expected

After a Subject

You need a verb.

• "The population __________ by 30% over the decade." → verb expected (increased, declined, grew)

After a Verb

You might need an object (noun), adverb, or complement.

• "Scientists discovered __________." → noun phrase expected

Handling Tricky Situations

When the Passage Uses Different Words

IELTS passages rarely use the same words as the questions. Be prepared for synonyms:

| Question word | Passage word | |--------------|--------------| | children | young people, minors, youths | | reduce | decrease, diminish, cut, lower | | important | significant, crucial, essential | | problem | issue, challenge, difficulty | | increase | rise, growth, expansion, surge |

Train yourself to look for meaning, not exact words.

When Multiple Words Could Fit

Sometimes you find a section where several words seem possible. In these cases:

1. Check the grammar constraint — only one option will be grammatically correct
2. Check the word limit — this may eliminate longer options
3. Check the meaning precisely — the correct answer matches the meaning of the question exactly

When Numbers Are Involved

If the instruction says "no more than two words and/or a number," remember:

• Numbers written as figures (2019, 150) count as one number
• Numbers written as words (fifteen, two hundred) count as words
• Hyphenated words (well-known, long-term) usually count as one word in IELTS

When You Cannot Find the Answer

If you have spent more than 90 seconds on one question:

1. Re-read the incomplete sentence and check whether you identified the correct key words
2. Consider whether the passage might use a completely different term for the concept
3. Check the paragraph after where you have been looking — you might have the location wrong
4. If still stuck, make your best guess and move on

Common Mistakes and How to Avoid Them

Mistake 1: Exceeding the Word Limit

Solution: Count every word carefully. Remember that articles (a, the) and prepositions count as words.

Mistake 2: Changing Word Forms

Solution: Copy the exact words from the passage. If the passage says "environmental pollution," write exactly that.

Mistake 3: Spelling Errors

Solution: Copy carefully. Even one misspelled letter means zero marks.

Mistake 4: Choosing Words from the Wrong Section

Solution: Use the sequential nature of the questions. Answers generally follow the order of the passage.

Mistake 5: Not Using Grammar as a Guide

Solution: Always check whether your answer creates a grammatically correct sentence.

Practice Exercise

Here is a mini practice exercise. Read the paragraph, then complete the sentences below (use NO MORE THAN TWO WORDS from the text).

"The discovery of penicillin in 1928 by Alexander Fleming revolutionised modern medicine. Before antibiotics, even minor infections could prove fatal. Fleming noticed that a mould called Penicillium notatum had contaminated one of his bacterial cultures and was destroying the bacteria around it. This accidental observation led to the development of the first widely used antibiotic, which has since saved countless lives worldwide."

1. Prior to antibiotics, people could die from relatively __________ infections.
2. Fleming observed that a __________ had destroyed bacteria in his culture.
3. The discovery of penicillin was described as an __________ observation.

Answers: 1. minor, 2. mould, 3. accidental

Building Your Skills

The best way to improve at sentence completion is through consistent practice with authentic IELTS materials. Focus on:

• Building your synonym vocabulary
• Practising grammar analysis of incomplete sentences
• Developing your scanning speed
• Working under timed conditions

CambPrep's reading exercises include sentence completion tasks with instant feedback and detailed explanations for every answer. You can practise under timed conditions to build the speed you need for test day.

If you want to assess your current reading level and identify specific areas for improvement, take a level test for a comprehensive evaluation.

Frequently Asked Questions

Do the answers always come in order in the passage?

In most cases, yes. The answers to sentence completion questions generally follow the order of the passage. If you found the answer to question 3 in paragraph 4, the answer to question 4 will typically be in paragraph 4 or later. This is very helpful for narrowing your search area.

Should I write the answer in capital letters?

You can write answers in either uppercase or lowercase — both are accepted. However, proper nouns (names of people, places, organisations) should be capitalised as they appear in the passage. To be safe, many candidates write all answers in uppercase.

What if a hyphenated word is the answer?

Hyphenated words like "well-known" or "state-of-the-art" are generally counted as single words in IELTS. If the word limit is "one word" and the answer is a hyphenated term, it should be acceptable. When in doubt, check how the word appears in the passage.

How is sentence completion different from summary completion?

Sentence completion gives you individual, independent sentences to complete. Summary completion gives you a connected paragraph with multiple blanks. The strategy is similar, but summary completion often covers a larger section of the passage and may include a word bank to choose from.