下面是小编精心整理的if当是否讲引导什么从句（共含10篇），仅供参考，大家一起来看看吧。同时，但愿您也能像本文投稿人“Dearu”一样，积极向本站投稿分享好文章。
Put your hand up if you need more paper.
若有人还要纸，请举手。
Only time will tell if the treatment has been successful.
只有时间才能证明这种疗法是否成功。
He must be 70 if he's a day!
他至少70岁了！
I don't care if I never see him again!
即使我永远再也见不到他，我也不在乎！
Call me if you have any problems regarding your work.
你如果还有什么工作方面的问题就给我打电话。
从句可放在主句前面，此时要用逗号分开，也可放在主句后面。
如：
1.If it doesn't rain tomorrow , we will go shopping .（if it doesn't rain tomorrow是从句）
= We will go shopping if it doesn't rain tomorrow.
如果明天不下雨，我们就去购物。
2.He will come if you invite him. (if you invite him 是从句）
=If you invite him , he will come .
如果你请他,他会来的。
if引导的从句称之为条件状语从句，在句子中作状语。主句用将来时态，而从句用一般现在时。
If I might just say something...
要是叫我说…
What if she forgets to bring it?
要是她忘记带来，会怎么样呢？
'And if I say no?' she ventured.
“那么我要是说不呢？”她试探说。
What difference will it make if he knows or not?
他知不知道有什么关系吗？
Please let me know how many are coming, if any.
请告诉我，如果有人要来的.话，有多少？
That was a disaster if ever there was one!
那确实是场灾难！
Put your hand up if you know the answer.
知道答案就举手。
If you love each other, why not get married?
要是你们彼此相爱，干吗不结婚呢？
If you don't believe me, go and see for yourself!
要是不信我说的，你自己去看看！
if做连词,主要有两个意思,“是否”,引导宾语从句；“如果”,引导状语从句：
一、if作为连词,引导条件状语从句,它表示的意思是“假如”“如果”等.在复合句中如果主句用将 来时,则if引导的状语从句用一般现在时.例如：
1.If itdoesn’train,we will go to the park next Sunday.如果天不下雨,下周星期天我们将去公园.
2.If you ask him,he will help you．如果你求他,
if从句中用过去式,表示不可能实现,大概不会实现或提出作为考虑的.假定条件.此时需要用虚拟语气,例如：
1.If you were a bird,you could fly.假使你是只鸟,你便会飞了.
2.If I asked him(if I were to ask him) for a loan,would he agree?如果我向他借贷,他会答应吗?
另外,if从句中用过去完成式,表示过去未实现的条件(例如由于不可能实现或某人之未能实行).例如：
1.If they had startedearlier,they would have arrivedin time．要是他们早些动身,他们便可及时到达了.
2.If they had not started when they did,they would not be here now．如果他们那时不动身,现在他们就不会在此地了.
二、if还可以引导让步状语从句.这时if当作“即使是”,“虽说”解.例如：
1.If she’s poor,at least she’s honest． 虽说她很穷,但至少她还是诚实的.
2.If I am wrong,you are wrong,too． 即使说我错了,那么你也不对.
3.I’ll do it,even if it takes me all the afternoon． 虽然会花费我一下午的时间,我还是要做这事.
三、if作为连词还可以引导宾语从句.引导宾语从句时和whether意思相同.例如：
1.Lily asked if ／ whether she liked it.莉莉问她是否喜欢它.
2.She asked if ／ whether they had a cotton one． 她问是否他们有一件棉织的.
Whether引导从句用法：
1.whether和if都可以表示“是否”，引导宾语从句。
2.当引导的从句中出现or not时，通常用whether，而不用if。
3.to+动词的结构（即动词不定式）前只能用whether。
4.介词prep.后只能用whether。
5.当宾语从句提到句首表示强调时，只能用whether引导，不能用if。
6.只能用whether引导主语、表语或同位语从句，不可用if。
What if she forgets to bring it?
要是她忘记带来，会怎么样呢？
'And if I say no?' she ventured.
“那么我要是说不呢？”她试探说。
She asked if I would help.
她问我是否会帮忙。
I'm not sure whether I should tell you this.
我拿不准该不该把这事告诉你。
She asked her boss whether she could have the day off.
她问老板可不可以让她请一天假。
You've got to go to school, whether you like it or not.
不管你喜欢不喜欢，你得上学。
It's doubtful whether the car will last another year.
这辆汽车未必还能用上一年。
It remains to be seen whether his project will fly.
他的计划能否成功尚需拭目以待。
So you're a runner, huh?
这么说，你是个跑步爱好者喽？
So it's a magic potion?
这么说它是一种魔药？
Sorry I took so long.
对不起，我用了这么长时间。
I don't really agree with that。
对此我不太赞同。
Do you need any help with that？
这事你需要帮忙吗？
Are you through with that newspaper？
你看完那份报纸了吗？
★ 定语从句
