初二下册英语unit 6句式语法

　　Unit 6 How long have you been collecting shells?

　　重点语法：现在完成进行时态

　　do/does 的现在完成进行时态形式：have/has been doing

　　do/does 的现在完成进行时态的被动语态：have/has been being done

　　现在完成进行时态所应用的场合：

　　①某事从过去发生一直持续到现在都在做

　　②过去发生的动作对现在造成影响

　　例：我已上了三年初中。

　　I have been in Junior School for 3 years.

　　自从那次他与我谈过心后，我天天都在进步。

　　I have been making progress since he talked with me that time.

　　现在完成进行时态的肯定句、否定句和疑问句形式：

　　肯定句例句：I have been skating for five hours.

　　否定句例句：I haven‘t been skating for five hours.

　　一般疑问句例句：Have you been skating for five hours?

　　特殊疑问句例句：How long have you been skating?

　　注意：瞬间动词不能和一段时间连用。

　　例句：你借这本书已经多长时间了?

　　How long have you been keeping this book?