if/ɪf/

conj.

➊ used to say that sth might happen

➋ used after “ask”, “know”, etc. to show one of two or more possibilities; whether

conj.

➊ 如果，假使：If I am free, I will go with you. 假如我有空，我会与你一起去。

◇[if + 虚拟语气] If you had worked harder, you could have passed the test. 假如你更努力点，就可以通过测验了。

◇If I were you, I would apologize to him. 我要是你，我要向他道歉。

◇Call the police if necessary. 有必要的话就打电话叫警察。

➋ 是否，是不是：I don't know if he is here. 我不知道他是否在这儿。

if only ... 要是…就好了：[用虚拟语气] If only I were a writer. 要是我是个作家就好了。

常犯错误

✗ If it will rain, we'll stay at home.

✓ If it rains, we'll stay at home. 假如下雨，我们就待在家里。

[✌if从句中不用将来时，要用一般现在时代替将来时。但will表示“愿意”时，可放在if从句中。]

用法虚拟从句If I were you中的were不能换为was，其他情况可用were或was，如：If I were（或was） rich, I would buy you anything you wanted.

辨析if; whether

辨析if only; only if