Practice Sentence Completion questions for the Cognitive Abilities Test — Grade 4 (Level 10). Every question includes a full explanation of why the correct answer is right and why the tempting distractors are wrong.
25 questions available · medium difficulty · CogAT Grade 4 · Free, no registration required
What Sentence Completion measures
A sentence is given with one word missing and the child chooses the word that best completes it. It tests whether a child can use the logic of a sentence rather than merely its grammar, which is why the wrong answers almost always fit grammatically and fail on sense.
What a grade 4 sentence completion question looks like
Longer sentences with more than one clause, and the deciding context often placed after the blank rather than before it. Words that reverse the meaning - although, but, instead, unless - appear far more often, and missing one flips the answer to its opposite.
At level 10 — grade 4
Level 10 lengthens the sentences and starts placing the deciding context after the blank rather than before it. Reversing words appear more often, and a fourth grader who has not been taught to watch for them will lose marks on items they otherwise understand completely.
Where children go wrong
Answering from the first half of a contrast
Sentences built on although or whereas set up two halves pointing opposite ways. Reading the first half and answering from it gives a word that fits everything before the comma and contradicts everything after it.
Losing the thread across clauses
When the context fixing the answer sits two clauses from the blank, holding it while reading the rest is the actual difficulty. Working out what the sentence is claiming before looking at the options keeps it from slipping.
Picking a word that is right in the wrong register
Two options can both mean roughly what the sentence needs while only one suits its tone. That distinction is tested deliberately at this level, and it depends on having met the words in real reading rather than in a list.
How to practise this at home
When you read together, stop occasionally before a word and ask what your child thinks is coming. That is the same skill the subtest measures, minus the answer choices. When practising actual items, insist they read the whole sentence aloud with their chosen word in place before committing - most careless errors do not survive being heard.
Common questions about Sentence Completion
Is my child being tested on grammar?
No. All the choices are grammatically possible, and that is deliberate. What is being tested is whether the sentence's meaning fixes which word belongs.
What if my child does not know one of the words?
They should eliminate what they can and guess, since there is no penalty for a wrong answer. Some items are winnable even with an unknown option, because the sentence rules the others out.
How is this different from a reading comprehension question?
It works on one sentence rather than a passage, and asks what fits rather than what was said. The underlying skill - using context to constrain meaning - is closely related.
10 example questions with full explanations. Use the interactive practice above to work through the complete set.
Question 1medium
The desert region receives very little rain, so few plants are able to ______ there.
- A.sink
- B.float
- C.survive✓
- D.sleep
Correct answer: C
Plants need water, and the sentence says the desert has very little rain, so the blank must be about staying alive. 'Survive' means to stay alive in hard conditions, making C correct. 'Sink' and 'float' both describe what happens in water rather than what plants do without it. 'Sleep' is something animals do, not a way plants respond to dryness.
Question 2easy
Maria studied every night for two weeks, ______ she felt confident on the day of the test.
- A.although
- B.unless
- C.before
- D.so✓
Correct answer: D
Feeling confident is the result of all that studying, so the blank needs a word that introduces a result. 'So' does that, making D correct. 'Although' would set up a contrast, as if confidence came in spite of studying. 'Unless' introduces a condition, and 'before' would only put the two events in time order without connecting them.
Question 3medium
The old wooden bridge was ______ enough to hold the heavy delivery truck.
- A.strong✓
- B.narrow
- C.tall
- D.short
Correct answer: A
Holding something heavy is about how much weight the bridge can take, so the blank must describe that. 'Strong' describes the ability to bear weight, making A correct. 'Narrow' and 'short' describe the bridge's size, which affects what fits on it rather than what weight it holds. 'Tall' describes height and has nothing to do with carrying a heavy load.
Question 4easy
We waited under the shop awning ______ the rain stopped, then walked home.
- A.since
- B.until✓
- C.during
- D.while
Correct answer: B
The waiting ends at the moment the rain stops, so the blank needs a word marking that end point. 'Until' marks where something stops, making B correct. 'During' and 'while' would mean the waiting happened at the same time as the rain stopping, which does not fit a moment. 'Since' talks about how long something has been true instead.
Question 5hard
The scientist recorded her observations ______ so that she would not forget any small detail.
- A.loudly
- B.slowly
- C.carefully✓
- D.rarely
Correct answer: C
Not forgetting small details means paying close attention while writing, so the blank must describe that kind of attention. 'Carefully' means with close attention, making C correct. 'Slowly' is the tempting wrong answer because careful work often takes time, but going slowly does not by itself keep details from being missed. 'Loudly' describes sound, and 'rarely' would mean she hardly recorded anything.
Question 6medium
Only ______ students had finished the project, so the teacher gave the class more time.
- A.most
- B.all
- C.many
- D.a few✓
Correct answer: D
The teacher gave more time, which only makes sense if most of the class was still working. 'A few' means a small number had finished, making D correct. 'Most' and 'many' would mean a large number were already done, so extra time would not be needed. 'All' would mean nobody needed more time at all.
Question 7medium
The instructions looked complicated, ______ the task turned out to be quite simple.
- A.so
- B.because
- C.but✓
- D.since
Correct answer: C
Looking complicated and turning out simple pull in opposite directions, so the blank must join two ideas that disagree. 'But' marks that contrast, making C correct. 'So' would mean the complicated instructions caused the task to be simple. 'Because' and 'since' both give a reason, which reverses the relationship instead of contrasting it.
Question 8hard
The second experiment took ______ time than the first, so the team finished ahead of schedule.
- A.more
- B.most
- C.much
- D.less✓
Correct answer: D
Finishing ahead of schedule means the second experiment was quicker, so the blank must show a smaller amount. 'Less' does that, making D correct. 'More' would mean extra time was needed, which would put the team behind. 'Most' compares three or more things rather than two, and 'much' does not work with 'than' in a comparison.
Question 9medium
The missing keys had slipped ______ the sofa cushions, where nobody thought to look.
- A.between✓
- B.above
- C.beyond
- D.across
Correct answer: A
Cushions sit side by side, and something hidden would slip into the narrow space separating them. 'Between' names that space, making A correct. 'Above' would leave the keys resting on top in plain view. 'Beyond' means past the sofa altogether, and 'across' describes moving from one side to the other rather than settling into a gap.
Question 10medium
The town built a new dam ______ prevent flooding during the heavy spring rains.
- A.although
- B.in order to✓
- C.instead of
- D.because of
Correct answer: B
Preventing flooding is the reason the dam was built, so the blank needs a phrase that introduces a purpose. 'In order to' does exactly that, making B correct. 'Because of' is the tempting wrong answer because it also gives a reason, but it points backwards to a cause rather than forwards to a goal. 'Although' sets up a contrast and 'instead of' offers a replacement.