Whether it is true or not ,I can’t say.
2）在介词后常用whether，不用if.
It depends on whether you can do the work well.
3)与不定时连用时，只能用whether。
He can’t decided whether to accept or refuse.
4)当与or not连用时，if或whether 均可，但or not 直接跟在连词后时，则只能用whether. Let me know whether/if you can come or not.
I don’t care whether or not he comes.
what 和how 引导的感叹句
1.how引导的感叹句：
1）How+形容词/副词（+主语+谓语+其他）！
How tall the tree is!
2)How+形容词+a/an+可数名词单数形式（+主语+谓语）！
How beautiful a birthday present!
2.what引导的感叹句：
1)what+形容词+a/an+可数名词单数形式（+主语+谓语+其他）！
2)what+形容词+可数名词复数形式（+主语+谓语+其他）！
What interesting stories they are!
3)what+形容词+不可数名词复数形式（+主语+谓语+其他）！
What fine weather!
注意:what引导的感叹句通常可与how引导的感叹句进行转换。
语法专练
1.用that,if,whether,what,how填空。
1）I don’t know ________to go to there.
2）I know ______he will come to attend the meeting.
3）I wonder ________I should wear a coat or not.
4）______an interesting story it is!
5）______beautiful the building is !
2.单项填空
1）-At present,many people like talking about “kuaidi”and “didi”.I really wonder
_________.
-You can order a taxi through them on your mobile phone easily!
A. how can I use them B.who uses them most C.what they are used for
2)—We will have a new foreign teacher this term. Do you know
—A policeman.
A. what he did B. what he was C. what his job is
3）-What about going to the South Lake for a picnic next weekend?
-OK!But I’m not sure ______it will rain.