before 句型小专题 讲义-2022届高三英语一轮复习

before 句型小专题 before 句型小专题 1、 before作介词： 1. 表时间：在….之前（注： before不能加一段时间） e.g. You shall arrive at school before 8:00 a.m. e.g. We can finish the task before Friday. e.g. People will prepare some gifts before Christmas. 三天前：three days ago √ before three days × 2. 表方位：在….之前= in front of… e.g. There is a student before the desk. e.g. The mountain appeared before us at once. e.g. He made a speech before the students. e.g. Don’t mention it before me. 3. 表顺序：先于..;在…之前 e.g. She ranks before you. 4. long before : 很久以前 before long : 不久以后 e.g. The work will be finished before long. e.g. She said she had heard of it long before. 2、 before作连词，引导时间状语从句 1. 在…之前 e.g. Think it over before you act. e.g. I knew the truth before you told me. 2. 趁着没….. e.g. Before the teacher found him, he ran out of the classroom. e.g. Before I forgot the words, I wrote them down immediately. 3. before sb. can/could do sth: 某人没来得及做…就…. e.g. Before I could say, he rushed out. e.g. Before I could answer the phone, it stopped ringing. e.g. 大家还没来得及告别，就毕业了。 Before we could say goodbye, we graduated 4. before句型：时态遵守 “主从句一致”或“主将从现”。 翻译：肯定句：过了多久才…. 否定句：没过多久就…… （1） It will be +时间段+ before….. （主将从现） （2） It was +时间段+ before….. （从句用一般过去时） e.g. It will be four years before he graduates. e.g. It won’t be a week before we meet again. e.g. It was some time before we realized the truth. e.g. It wasn’t two years before he left the country. e.g. How long do you think it will be before China sends a manned spaceship to the moon? before练习题： 1. The American Civil War lasted four years _______ the North won in the end. 2. He made a mistake, but then he corrected the situation ________ it got worse. 3. It was evening ________ we reached the little town of Winchester. 4. It was some time _________ we found the mistake. 5. Scientists say it may be five or six years _____it is possible to test this medicine on human patients. 6. It will not be long _______ he _______ (know) the result of the experiment. 7