Affect or Effect, Fewer or Less and Other Tricky Pairs

01Verb or noun?

Affect is usually a verb: stress affects sleep. Effect is usually a noun: side effects, take effect. Advise is the verb and ends in a z sound; advice is the noun, ends in an s sound, and is uncountable: some advice, a piece of advice.

• The heat affects my allergies.
• The new law takes effect in January.
• My doctor advised me to rest.
• Can I give you some advice?

02Fewer or less?

Use fewer with things you can count (fewer cars, fewer emails) and less with things you can't count (less traffic, less sugar). With amounts of money, time and distance, Americans say less than: less than $20, less than an hour.

• We had fewer customers today.
• I drink less coffee than I used to.
• The drive takes less than an hour.

03Lie or lay? Rise or raise?

Lay and raise take an object: you lay something down, you raise something. Lie and rise don't: you lie down, prices rise. The hard part: the past of lie is lay. In casual speech you'll hear "I'm going to lay down," but in writing, use lie.

04Borrow or lend? Farther or further?

You borrow something from someone; they lend it to you. For physical distance, Americans prefer farther. For more or additional, use only further: further questions, until further notice.

• Can I borrow your pen?
• Could you lend me your notes?
• How much farther is the hotel?
• Call us if you need further help.

05Look-alike pairs

Principal means main, the head of a school, or the amount of a loan. Principle is a rule or belief. Complement means go well with; compliment means praise, and complimentary also means free. Economic is about the economy; economical means it saves money.

06Common mistakes