if的用法英语是否

if有是否;如果;即使;每当等意思，那么你知道if的用法吗?下面跟着我一起来学习一下，希望对大家的学习有所帮助!

if的用法大全：

if的用法1：if作为从属连词,可引导条件状语从句、让步状语从句和名词从句。

if的用法2：if引导条件状语从句,从句可为真实条件从句,也可为虚拟条件从句。如为真实条件从句,谓语用陈述语气,表示可能性很大,作“假使”“如果”解,通常用一般现在时代替一般将来时; 如果if从句中用will,表示意愿。从句如为虚拟条件从句,谓语动词要用虚拟语气,表示可能性不大或与过去事实相反,作“要是,假如”解。可指过去的情况,也可指现在和将来的情况。指将来情况时可用were to或should。在现代口语中,一、三人称后常用was代替were。if引导的虚拟条件句中,助动词were,should,had可以移至主语前,此时if可省略。

if的用法3：if引导的条件从句中可以省略be和主语。

if的用法4：if引导的条件从句,有时后接only以加强其语气,表示说话人非常盼望某人提出的条件能够实现。

if的用法5：if可引导让步状语从句,作“虽然,即使”解,常和even连用。

if的用法6：if可引导名词性从句,作“是否”解,常放在ask, doubt, know, learn, see, wonder等动词后。一般用在口语中,而且不能用于句首。

if的用法例句：

1. If you wait, all that happens is that you get older.

如果你等待，发生的只有变老。

2. If you love life, life will love you back.

热爱生活，生活也会厚爱你。

3. If you're not satisfied with the life you're living, don't just complain. Do something about it.

对于现况的不满，不能只是抱怨，要有勇气作出改变。

4. If you're lonely when you're alone, you're in bad company.--Jean Paul Sartre

如果你独处时感到寂寞，说明没有把自己陪好。

5. Friendship means understanding, not agreement. It means forgiveness, not forgetting.It means the memories last, even if contact is lost.

友情是理解，不是妥协;是原谅，不是遗忘。即使不联系，感情依然在。

6. You have to do everything you can. You have to work your hardest. And if you do, if you stay positive, then you have a shot at a silver lining.

你必须全力以赴，最大限度地去努力。如果你这么做，并且保持乐观，你就会看见乌云背后的幸福线。

7. The house seemed muted, hushed as if it had been deserted.

房子里似乎悄然无声，安静得好像已经没人在住一样。

8. He'd phoned Laura to see if she was better.

他打电话给劳拉看她是不是好些了。

9. Things might have been different if I'd talked a bit more.

如果当时我再多说一点的话，结果或许会不一样。

10. If your skin becomes red, sore or very scaly, consult your doctor.

如果皮肤发红、瘙痒或脱皮，要向医生咨询。

11. If you build more plastics into cars, the car lasts longer.

如果汽车采用更多塑料元件，寿命会更长一些。

12. More people would be attracted to cycling if conditions were right.

如果天气适宜，会有更多的人被吸引到骑自行车的行列中来。

13. But legal experts are not sure if such a charge can stick.

但法律专家们不能肯定这一指控是否成立。

14. If they value these data, let them pay for them.

他们要是看重这些数据，就让他们出钱买。

15. They get angry if they think they are being treated disrespectfully.

他们要是觉得受到了怠慢，就会大动肝火。

if的用法如下：

1、表示条件：如果。主句用将来时，if从句用现在时表示将来。

He will come if you invite him.

2、是否：whether连接宾语从句。

I wonder if he is ill.

3、表示虚拟：假如，要是。时态：可以表示过去，现在和将来的情况，它的基本特点是时态退后。

A、同现在事实相反的假设。

一般过去时should(would)+动词原形：If they were here,they would help you.

B、表示于过去事实相反的假设。

过去完成时should(would)have+过去分词：If she had worked harder,she would have succeeded.

C、表示对将来的假想。

一般过去时should+动词原形：If you succeeded,everything should be all right.

were+不定式would+动词原形：If you should succeed,everything would be all right.

should+动词原形：If you were to succeed,everything should be all right.