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Module five of the writing course: commonly confused words in academic writing such as affect and effect, its and it's, comprise and consist, with four practice questions, a ranking task, a final self-check with model answers, and tap-for-Japanese help, for Japanese researchers at B1 and B2 levels
Words with a dotted line have help in Japanese. Tap them. 点線のある単語は日本語の説明があります。
Stage 1 · Foundations · Module 5
Commonly confused words
A few word pairs look or sound alike but mean different things. Reviewers notice these quickly, and a wrong one can change your meaning. Here are the pairs that matter most in research writing.
The drug had a strong affect on it's target cells. (two confused words)
The drug had a strong effect on its target cells.
The pairs worth memorising
affect / effect
Affect is usually a verb (to change something). Effect is usually a noun (the result). "X affects Y" · "X has an effect on Y"
its / it's
Its means "belonging to it". It's means "it is" — a contraction, so it is avoided in papers anyway. "the cell and its wall"
comprise / consist
Both mean "to be made up of", but consist takes of and comprise does not. "consists of three parts" · "comprises three parts"
principle / principal
Principle is a noun (a rule or belief). Principal means "main". "a basic principle" · "the principal cause"
affect or effect?
"Temperature can strongly ______ the rate of reaction." (you need the verb — to change something)
affecteffecteffectsaffects
affect or effect? (the other one)
"The treatment had a clear ______ on recovery time." (you need the noun — the result)
effectaffectaffectsaffected
its or it's?
"Each molecule keeps ______ shape under pressure." (belonging to the molecule)
itsit'sits'it is
comprise or consist?
"The sample ______ of forty participants." (notice the word "of")
consistscomprisescomprises ofconsist
Put these in order — drag the best to the top
All three try to say the same thing. Drag the one with no confused-word errors to the top.
Best — all words correct
1The affect was clear, and it's structure consists of two parts.
2The effect was clear, and its structure comprises of two parts.
3The effect was clear, and its structure consists of two parts.
Worst — most confused-word errors
Final self-check — choose the correct word
Three sentences. For each, tap the version with the correct word. You will see at once if it is right.
Sentence 1 — affect or effect
Smoking has a serious affect on the lungs.
Smoking has a serious effect on the lungs.
Smoking has a serious affects on the lungs.
Sentence 2 — its or it's
The system increased its output over time.
The system increased it's output over time.
The system increased its' output over time.
Sentence 3 — comprise or consist
The course comprises of five modules.
The course consists of five modules.
The course consist of five modules.
Model answers 1. Smoking has a serious effect on the lungs. — noun (the result). 2. The system increased its output over time. — possessive, no apostrophe. 3. The course consists of five modules. — consist always takes "of". A quick test for affect/effect: if you can put "the" or "an" in front, you need the noun "effect".
Bonus worksheet
Keep practising away from the screen — download this module’s worksheet as a printable PDF.