五、现在完成时:
1.概念:过去发生或已经完成的动作对现在造成的影响或结果,或从过去已经开始,持续到现在的动作或状态.
2.时间状语:recently,lately,since…for…,inthepastfewyears,etc.
3.基本结构:have/has+done
4.否定形式:have/has+not+done.
5.一般疑问句:have或has.
6.例句:I'vewrittenanarticle.
Ithasbeenrainingthesedays.
Ihaveansweredthequesion
Thequesipnhasbeensolved
Computerhasbeeninvitedformanyyears
HaveyoubeentotheUSA?
Hehasgonetohome