if

中文： 是否、如果、要是、如

1. Supposing that, assuming that, in the circumstances that; suppositive used to introduce a condition that may be (or prove to be) either true or false. · I'll do it next week if I have time.· Fetch me a cold beer if there's one in the fridge.
2. A keyword that invokes conditional processing: in the event that a given condition is true, execute the given statement(s) (otherwise execute other statements). · if A then B else C
3. Supposing that; used with past or past perfect subjunctive to indicate a counterfactual or hypothetical condition. · If she hadn't told me, I wouldn't know.· If he understood how this made me feel right now, he'd be O.K. with it too.
4. Even if; even in the circumstances that. · I wouldn't marry you if you were the last man on earth.· You're finishing your chowder if you sit there all afternoon!
5. Considering the fact that; given that; introducing a condition that is known to be true. · The drain's blocked — and if the drain's blocked, the water won't flow.
6. When; whenever; every time that. · If you heat water to 100° C, it boils.· If it rains, it pours.
7. Although; used to introduce a concession; may..but. · He was a great friend, if a little stingy at the bar.· She won her team's admiration, if not the award, for her performance.
8. While; used to introduce a contrast. (literary) · If tea is expensive, coffee is completely unaffordable.