2019学年度北师大版选修八Unit23ConflictLesson 4课时语法精讲 学案设计

　　[语法·预备役]

　　用括号里动词的正确形式完成下面的句子

　　1．Why ____________ (have) you ____________ (be) in touch?

　　答案：haven't；been

　　2．You ____________ (have) my e­mail for ages!

　　答案：have had

　　3．At least by the time I get back I ____________ (read) that awfully boring book that my history teacher has made me read over the holidays.

　　答案：will have read

　　4．If I ____________ (realise) it was that dangerous I ____________ never ____________ (stand) so close!

　　答案：had realised；would；have stood

　　5．I suppose they ____________ (know) me since I was a baby.

　　答案：must have known

　　6．I ____________ (be) out helping my grandfather with his fence.

　　答案：should have been

　　[语法·讲座]

　　表达完成的动词形式

　　1．现在完成时

　　(1)现在完成时由"have/has＋过去分词"构成，主要有两个含义：

　　①表示动作发生在过去，但对现在有影响，有时无时间状语，有时和一些所指时间不具体的时间状语连用，如：just, yet, already, before, recently, lately等。

　　②表示从过去某一时间开始一直延续到现在并还可能继续延续下去的动作，用于延续性动词，且句中常带有表示一段时间的时间状语，如：since, for等。

(2)现在完成时和一般过去时都能表示过去发生过的动作，但现在完成时