Affect vs. Effect, Fewer vs. Less and Other Pairs That Trip People Up

Affect and effect

In everyday writing, affect is a verb meaning to influence, and effect is a noun meaning a result.

The weather will affect our plans. The weather had a big effect on our plans.

Effect can also be a verb meaning to bring about, as in 'to effect change', but you will rarely need that.

Fewer and less

Use fewer with things you can count one by one. Use less with amounts you cannot count.

fewer mistakes, fewer people, fewer emails less time, less water, less noise

Then and than

Then is about time or order. Than is for comparing.

We ate, and then we left. She runs faster than I do.

Lose and loose

Lose is a verb that means to misplace something or to fail to win. Loose is an adjective that means not tight.

Don't lose your keys. This screw is loose.

Advice and advise

Advice is the noun and advise is the verb. Notice the sound: advice ends in a soft s, advise in a z sound.

Thanks for the advice. I advise you to wait.

Principal and principle

A principal is the head of a school or the main thing. A principle is a rule or belief.

The principal welcomed the new students. Honesty is a principle I live by.

Every day and everyday

Every day means each day. Everyday is one word when it describes something ordinary.

I walk to work every day. These are my everyday shoes.

Could have, not could of

'Could of' is a spelling of how 'could've' sounds. The written form is always 'could have', and the same goes for would have and should have.

More pairs worth knowing

A few more pairs cause trouble in everyday writing. 'Accept' means to receive, while 'except' means to leave out. 'Complement' means to complete or go well with, while 'compliment' is praise. 'Stationary' means not moving, and 'stationery' is paper and pens. 'Whose' asks about ownership, while 'who's' is short for 'who is'.

I accept all the terms except the last one. The wine complements the meal, and the chef received many compliments.

How to learn pairs without memorising lists

Pick the two or three pairs you personally confuse, and write one example sentence for each in your own words. Keep them in a note and reread them before important writing. Learning pairs in context works better than studying a long list, because your memory attaches the word to a situation instead of an abstract rule.

FAQ

Q. Is it wrong to say 'less people'?

In careful writing, 'fewer people' is preferred because people can be counted. 'Less' with countable nouns is common in speech, but many style guides call it an error.

Q. When is 'effect' a verb?

In the formal phrase 'to effect change', it means to bring about. In everyday writing you will almost always want 'affect' as the verb.

Q. How can I remember lose and loose?

Loose has two o's, like the extra room in a loose shirt. Lose has one, because something is gone.