used to show that something depends on something else
If it rains, we will stay inside.
如果下雨,我們就待在室內。
when something always happens
If you heat ice, it melts.
如果你加熱冰,它就會融化。
used to talk about possibilities
I don't know if I should go.
我不知道我是否應該去。
used with feeling words
I wonder if you can help me.
我想知道你是否能幫助我。
used to say something is not important
If he is late, it's not a big problem.
如果他遲到,也不是什麼大問題。
used to ask someone to think about something
If you consider the time, we should leave now.
如果你考慮時間,我們現在應該離開了。
used to show a small contrast
She is nice, if a bit shy.
她人很好,雖然有點害羞。
used to ask politely
If you would wait here, I will get help.
如果您能在這裡等候,我會去尋求幫助。
used to suggest something politely
If I may suggest, we could try again.
如果我可以建議的話,我們可以再試一次。
something that might not happen
Winning is a big if, but we can hope.
獲勝是個很大的未知數,但我們可以抱有希望。