if

US /ɪf/
UK /ɪf/
"if" picture
1.

如果, 要是

introducing a conditional clause; on the condition that; provided that

:
If it rains, we will stay home.
如果下雨,我们就待在家里。
Let me know if you need help.
如果你需要帮助,告诉我。
2.

是否, 是不是

introducing an indirect question involving whether or a choice between alternatives

:
I wonder if she will come.
我想知道她是否会来。
See if the door is locked.
看看门是否锁了。
3.

要是, 但愿

expressing a wish or regret

:
If only I had known!
要是我早知道就好了!
If only I could fly.
要是我能飞就好了。
1.

如果, 假设

a condition or supposition

:
There are too many ifs and buts in your argument.
你的论点中有太多的如果和但是。
We need to consider all the ifs before making a decision.
在做决定之前,我们需要考虑所有的可能性