一个初中英语问题

Question

We are not sure if it (will rain ) tomorrow. If it ( rians ) ,our meeting will be put off.
第二句是条件状语从句，所以用主将从现，第一句不是时间状语从句，所以不用主将从现
这种思维对么

Answer 1

这样的思维是正确的
先看一下if的用法
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.
如果你请他,他会来的。
2. (表示虚拟)假如,要是
1）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。
句型 ： 条件从句 主句
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。
句型： 条件从句 主句
过去完成时 should(would) have+ 过去分词
If she had worked harder, she would have succeeded.
The rice would not have been burnt if you had been more careful.
If my lawyer had been here last Saturday, he would have prevented me from going.

If he had come yesterday, I should / would have told him about it.
含义：He did not come yesterday, so I did not tell him about it.
If he had not been ill and missed many classes, he would have made greater progress.
含义： He was ill and missed many lessons, so he did not make greater progress.
c. 表示对将来的假想
句型： 条件从句 主句
一般过去时 should+ 动词原形
were+ 不定式 would + 动词原形
should+ 动词原形
If you succeeded, everything would be all right.
If you should succeed, everything would be all right.
If you were to succeed, everything would be all right.
3. 是否 = whether 连接宾语从句
I wonder if she is ill.
不知她是否病了。
就这连两个句子来说
If it ( rians ) ,our meeting will be put off. 属于上面用法的第一种情况，(表示条件)如果 ,主句用将来时，if从句用现在时表示将来（即主将从现）

We are not sure if it (will rain ) tomorrow 属于上面用法的第三种情况， 是否 = whether 连接宾语从句

不清楚的地方请继续发问！

Answer 2

是的, if既可引导条件状语从句(如果), 又可引导宾语从句(是否);

当if引导条件状语从句,作(如果)讲时, 用"主将从现"原则;

当if 引导宾语从句,作(是否)讲时, 就不能用"主将从现"原则, 而是需要用什么时态就用什么时态;

第二句是条件状语从句，所以用主将从现，第一句不是条件状语从句，所以不用主将从现

Answer 3

对的
第一个if是是否的意思
引导宾语从句
第二个if 是如果，引导条件从句，所以遵循主将从现
我们不确定明天是否会下雨，如果下雨，我们的会议就会被推迟

Answer 4

是对的
We are not sure if it (will rain) tomorrow.　通常认为形容词(sure等)后跟的是宾语从句。

If it ( rians ) ,our meeting will be put off.　前半句为条件状语从句，从句应用现在时表将来

Answer 5

在条件状语从句和时间状语从句中 都是你说的主将从现。
第一句是宾语从句，所以要用它真实的时态。

Answer 6

对的，就是按照这样思维想，然后第一句按平时的该用什么时态就用什么时态