We use the conjunction unless to mean ‘except if’. The clause which follows unless is a subordinate clause (sc): it needs a main clause (mc) to make a complete sentence.

The meaning of UNLESS is except on the condition that : under any other circumstance than. How to use unless in a sentence.

UNLESS definition: except under the circumstances that. See examples of unless used in a sentence.

Unless is a subordinating conjunction used to mean “if not” or to introduce a condition that would prevent something from happening. It is used to express a negative condition — a situation where …

Don't use 'unless' to say that something would happen or be true if particular circumstances did not exist. For example, if you have a cold, don't say ' I would go to the party unless I had this cold '.

Unless is used to introduce the only situation in which something will take place or be true. In the 1940s, unless she wore gloves a woman was not properly dressed...

There are 12 meanings listed in OED's entry for the word unless, seven of which are labelled obsolete. See ‘Meaning & use’ for definitions, usage, and quotation evidence.

Unless means the same as if...not. Like if, unless is followed by a present tense, a past tense, or a past perfect tense (never by a conditional). Unless is used instead of if...not in conditional sentences of all …

Jan 20, 2026 · I’m leaving unless I get a pay rise. You can't go out unless it stops raining. Unless part of the staff, you are not allowed beyond this point.

Unless means 'except if'. We use unless to say that there may be an exception and that this exception will change the situation. We're playing tennis tomorrow unless it rains. (= We're playing tennis …