Expressions

Meaning and usage

Example

unless

(если … не)

- means “except if”.

- is followed by an affirmative verb

-is used instead of “if...not”

Our director would not have signed the contract unless she had had a lawyer present.

as long as

(если; при условии, что, если только).

-means ‘if”

-is more common in speaking

- emphasizes condition

We could forgive him as long as he apologized to us.

on condition that

- more official (formal) than as long as

- more common in writing

You may take two days off on condition that you work on the weekend.

provided (that)

= as long as

-is more formal and more common in written language

-emphasizes condition

Provided you pay me back soon (condition), I will lend you the money.

supposing

- invites to imagine a situation

-smth might happen.

-can be used without the main clause.

Supposing (that) you are wrong, what will you do then?

Supposing you can't find a job?

only if

-makes the condition more restrictive

- if the if-clause is first, the subject and the auxiliary in the main clause are inverted.

You can go out only if you do your homework.

Only if you like classical music is it worth coming tonight.

in case

(на случай если; на тот случай, если)

- expresses a possibility

-is used to talk about doing smth to avoid a possible problem.

-can be used to shorten an if-clause.

Take your cell phone with you in case you need to call me.

If there is a fire, leave the room.= In case of fire, leave the room.