現(xiàn)在完成時

1.概念：過去發(fā)生或已經(jīng)完成的動作對現(xiàn)在造成的影響或結(jié)果，或從過去已經(jīng)開始，持續(xù)到現(xiàn)在的動作或狀態(tài)。

2.時間狀語：yet,already,just,never,ever,so far,by now,since+時間點，for+時間段，recently, lately, in the past few years, etc.

3.基本結(jié)構(gòu)：主語+have/has +p.p（過去分詞）+其他

4.否定形式：主語+have/has + not +p.p（過去分詞）+其他

5.一般疑問句：have或has。

6.例句：I've written an article.

? ? ? ? ? ?The countryside has changed a lot in the past few years.