Lesson 15 of 58 intermediate

Reading: Sentence Completion & Short Answer

Perfect the art of extracting precise information from the passage within strict word limits

Open interactive version (quiz + challenge)

Real-world analogy

Sentence Completion is like a jigsaw puzzle where the sentence has one missing piece and you must find it in the passage. Short Answer is like a quiz show — the host asks a direct question and you must find the exact answer from the text, not make one up. Both reward precision: the right information in the right number of words.

What is it?

Sentence Completion requires you to finish incomplete sentences using words taken directly from the passage, within a specified word limit. Short Answer requires you to answer factual questions (Who, What, When, Where, How many) using words from the passage. Both types test your ability to locate precise information and transfer it accurately without changing the original wording.

Real-world relevance

These skills mirror what you do when filling out forms. A visa application might ask "Purpose of visit" and you must write a concise, accurate answer. A medical form asks "Date of last vaccination" and you check your records for the exact date. Precision, brevity, and accuracy — exactly what IELTS tests.

Key points

Sentence Completion Format — You receive incomplete sentences and must complete them using words from the passage. The instructions specify a word limit, typically "NO MORE THAN TWO WORDS" or "NO MORE THAN THREE WORDS AND/OR A NUMBER." You must take words directly from the passage — you cannot paraphrase or use synonyms.
Short Answer Format — You receive direct questions (Who? What? When? Where? How many?) and must answer using words from the passage within a word limit. Like Sentence Completion, your answer must come from the passage text. These questions test your ability to locate and extract specific factual information quickly.
Read the Instruction Carefully — The word limit instruction is critical and varies between question sets. "No more than TWO words" means 1 or 2 words. "No more than THREE words AND/OR A NUMBER" means up to 3 words, optionally with a number like "350 million people." If you exceed the word limit, the answer is marked wrong even if the information is correct.
Grammar Fit Test — Your answer must fit grammatically into the sentence. If the gap comes after "the," you need a noun or noun phrase. If it comes after "was," you might need a past participle or adjective. Read the completed sentence aloud — if it sounds grammatically wrong, your answer is likely incorrect.
Following Passage Order — Sentence Completion and Short Answer questions follow the order of the passage. Question 1 is answered from an earlier section than question 2. Use this to progressively move through the passage rather than re-reading the whole text for each question. This saves significant time.
Synonym Bridge — The question uses different words from the passage (paraphrasing), but your ANSWER must use the passage's exact words. So the question might say "financial support" but the passage says "funding" — your answer is "funding." Build a bridge: question vocabulary leads you to the passage location, then you copy the passage vocabulary for your answer.
Number and Unit Rules — Numbers written as figures (42, 3.5, 200,000) count as one word. Units and currencies attached to numbers are separate: "42 million" is two words, "300 km" is two words, but "42%" is one word. Dates like "1990" are one word. Always double-check whether a number counts toward your word limit.
Avoiding Over-Answering — A common mistake is including unnecessary words. If the answer is "solar energy" and you write "using solar energy," you have exceeded the limit and will lose the mark. Extract only what is needed to complete the sentence grammatically and meaningfully. Less is usually more.
Short Answer Precision — Short Answer questions ask things like "What year did X happen?" or "How many people were affected?" Your answer must be precise: "1997" not "in the late 1990s," and "2.5 million" not "millions." The passage will contain the exact information; your job is to find it and copy it accurately.

Code example

PASSAGE:

Coral Reef Conservation

The Great Barrier Reef, stretching 2,300 kilometres along
Australia's northeast coast, is the world's largest coral
reef system. It comprises over 2,900 individual reefs and
supports approximately 1,500 species of fish, making it
one of the most biodiverse ecosystems on Earth.

Coral bleaching — caused when rising ocean temperatures
force corals to expel the symbiotic algae that give them
colour and nutrients — has intensified dramatically. The
reef experienced unprecedented mass bleaching events in
2016, 2017, 2020, and 2022. Marine biologist Dr. Terry
Hughes, who led aerial surveys of the damage, described
the 2016 event as "the worst in recorded history."

Conservation efforts have taken multiple forms. The
Australian government committed 1.2 billion dollars to
the Reef 2050 Plan, focusing on water quality improvement
and crown-of-thorns starfish control. Local initiatives
include coral gardening, where fragments of resilient
coral species are grown in underwater nurseries and
transplanted onto damaged reef sections.

SENTENCE COMPLETION (No more than THREE words):

1. The Great Barrier Reef runs along Australia's
   _______ coast.
   Scan for: location + coast
   Passage: "along Australia's northeast coast"
   Answer: northeast

2. Corals bleach because they lose the _______ that
   provide their colour.
   Scan for: cause of bleaching + colour
   Passage: "expel the symbiotic algae that give them
   colour and nutrients"
   Answer: symbiotic algae

3. The Australian government allocated _______ to the
   Reef 2050 Plan.
   Scan for: government + amount + Reef 2050
   Passage: "committed 1.2 billion dollars"
   Answer: 1.2 billion dollars (3 words - within limit)

SHORT ANSWER (No more than TWO words):

4. Who led aerial surveys of the bleaching damage?
   Scan for: aerial surveys + person
   Passage: "Dr. Terry Hughes, who led aerial surveys"
   Answer: Terry Hughes (or Dr. Terry Hughes = 3 words,
   EXCEEDS the limit, so just "Terry Hughes")

5. What is grown in underwater nurseries?
   Scan for: underwater nurseries + what is grown
   Passage: "fragments of resilient coral species are
   grown in underwater nurseries"
   Answer: coral fragments (wait - passage says
   "fragments of resilient coral species" - we need
   passage words within 2-word limit)
   Better answer: coral species? No - "fragments" is key
   Answer: coral fragments? Not exact passage words.
   Correct answer from passage: coral species

Line-by-line walkthrough

1. The passage covers three areas: reef facts and biodiversity, coral bleaching events, and conservation efforts.
2. For question 1, we scan for "coast" and find "northeast coast" in paragraph 1. Only one word is needed: "northeast."
3. For question 2, the key concept is what causes colour in corals. The passage says "symbiotic algae that give them colour" — so the answer is "symbiotic algae" (2 words, within the 3-word limit).
4. For question 3, we need an amount + plan name. "1.2 billion dollars" is 3 words — exactly at the limit. Writing "1.2 billion Australian dollars" would be 4 words and wrong.
5. For short answer 4, the question asks WHO — we need a person. "Dr. Terry Hughes" is 3 words but the limit is 2. We write "Terry Hughes" to stay within the limit.
6. Question 5 shows a real dilemma: the passage says "fragments of resilient coral species" but we need 2 words. This demonstrates why reading the exact passage wording matters.
7. Always count your words BEFORE writing your answer on the answer sheet. This simple habit prevents the most common error in these question types.

Spot the bug

A student's answers (word limit: NO MORE THAN TWO WORDS):

Q: How long is the Great Barrier Reef?
Student answer: "2,300 kilometres long"

Q: What event did Dr. Hughes call "the worst in
   recorded history"?
Student answer: "the mass bleaching"

Q: What does the Reef 2050 Plan focus on?
Student answer: "water quality"

Need a hint?

Check each answer for word count violations and whether the words are taken exactly from the passage.

Show answer

Answer 1: "2,300 kilometres long" is THREE words — exceeds the two-word limit. Correct answer: "2,300 kilometres." Answer 2: "the mass bleaching" is THREE words. Also, you should not include "the" unless it is part of a proper noun. Correct answer: "mass bleaching" or the specific year "2016 event." Answer 3: "water quality" is correct — two words taken directly from the passage. However, the passage actually says the plan focuses on "water quality improvement AND crown-of-thorns starfish control." Since the question asks what it focuses on (singular), and the word limit is two, "water quality" is the best available answer.

Explain like I'm 5

Imagine a colouring book where some words are missing from a sentence: "The cat sat on the ___." You have to look at the picture (the passage) and find exactly what the cat is sitting on. You cannot guess "chair" if the picture shows a mat. And you cannot write "the big blue mat" if you are only allowed two words. You write "blue mat" — exactly from the picture, exactly the right number of words.

Fun fact

The word limit rule catches thousands of IELTS candidates every year. In one testing centre report, 12% of all Sentence Completion answers that contained the correct information were marked wrong solely because they exceeded the word limit. Always count your words before writing your final answer!

Hands-on challenge

Using the coral reef passage above, write 3 more Sentence Completion questions and 2 Short Answer questions with a "NO MORE THAN TWO WORDS" limit. Make sure each answer can be found directly in the passage text. Then, take a new passage from a Cambridge IELTS book or the British Council website and practise 10 Sentence Completion questions under timed conditions (15 minutes). Count how many you got right and how many you lost due to word limit violations.

More resources

IELTS Reading: Sentence Completion Tips (IELTS Liz)
IELTS Reading Practice - Sentence Completion (British Council)
Short Answer Question Strategy (IELTS.org)
Cambridge IELTS 16 Academic Reading Tests (Cambridge)

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