第1个回答 2022-10-21
0. General conditionals 用法：用于讲事实
不变定律等等 句式： if-clause: present simple main clause: present simple 例子： a. If we eat contaminated food
we bee ill. b. If we boil water to 100oC
it changes into steam. ==================================================== 1. Open present or future conditionals 用法：有可能发生之事 句式： if-clause: present simple main clause: will + infinitive without to 例子： a. If you want to read the book
i will lend it to you. b. If it rains tomorrow morning
we will cancel our piic. ==================================================== 2. Unreal present of future conditionals 用法：不可能发生之事(现在/将来) 句式： if-clause: past simple main clause: would + infinitive without to 例子： a. I am busy now. If i had time
i would help you. b. I don't have a car. If i had one
i would take you for a ride. ==================================================== 3. Unreal past conditionals 用法：不可能发生之事(过去) 句式： if-clause: past perfect main clause: would + have + past participle 例子： a. If we had taken the 7:20 ferry
we would have been involved in the accident. b. If the driver had been driving slowly
he would have been able to stop in time to avoid the accident. ====================================================
参考: Certificate English Usage Fourth Edition by C.Harris
If Type 0
参考: owly.im/a0na6