【基本用法】 “过发现影”--- 表示过去发生，对现在造成了影响。

  e.g. Their parents have known the good news.They look excited.

 “过发持续”--- 表示从过去开始，持续到现在的动作或状态。

    e.g. I have learned English for 10 years.

   “经历”          --- 表示曾经做过某事，或曾做过n次

     e.g. I have seen the film Titannic twice.

【时间状语】   already, just, yet, since, since then, for, recently / lately,

   so far = till / until now = up to now, in the last / past few years,

    How long…ever, never, before, once, …times

【重难点】   延续性与非延续性动词的用法

什么时候才必须用延续性动词？        出现how long, for+时间段, since+时间点

非延续性动词转化

▲ 高频考点

 borrow → keep                                        buy → have

 finish / end → be over                         begin / start → be on

  open → be open                                        die → be dead

   join → be in / be a…member                 leave →be away（from）

   ▲ 需了解记忆

    get up → be up                                        fall asleep → be asleep

    fall ill → be ill,                    lose → be lost

    become → be                                        return / come back / get back → be back

    close → be closed                                catch / get a cold → have a cold

    arrive /come / go / move / reach /get to → be in /at / be here /be there

【易错点】   in the past few years (不是 a few)

   have been to, have gone to和have been in的区别

   already与yet区别

   since+时间点，for+时间段（since 3 years ago; for 3 years）

   since 引导的从句要用一般过去时

   It is /has been + 时间段 + since + 从句（一般过去时）

   He came to our school in 2000, since then he has taught English here.