現(xiàn)在完成時構(gòu)成：主語+ 助動詞have， has+ 過去分詞

    用法：1 ）表示過去發(fā)生的和現(xiàn)在有某種聯(lián)系的動作，常和just， usually，
already ， since等時間副詞連用。

    I have just had lunch.（飽了，不用再吃了。）

    He has had a cup of tea.（不渴了，不用再喝。）

    They have already had their holiday.（不能再度假了。）

    The boy has already read the book.（已經(jīng)知道書的內(nèi)容了，不用再看了。）

    2 ）詢問別人是否做過某事一般用現(xiàn)在完成時：Have you finished your homework？

    Have you been to Beijing？

    Have he seen the film ？

    3 ）表示開始于過去并持續(xù)到現(xiàn)在的動作I have lived in Beijing for twenty
years. I have worked for this school for 1 year. 4）表示一種經(jīng)歷，經(jīng)驗
：去過…地方，做過…事情，經(jīng)歷過…事情I have never had a bath. I have
never seen a film. I have never been to cinema. I have ever been to Paris.
Have been to表示去過，have gone to表示去了I have been to London.（人已
經(jīng)回來）

    He has gone to London.（人還在那里）

    5 ）表示一種結(jié)果，一般不和時間副詞聯(lián)用I have lost my pen. I have hurt
myself. He has become a teacher. She has broken my heart.

    句型變化：★變疑問句將助動詞移到句首，變否定句在助動詞后面加not. Have
you lost your pen ？ I have not lost my pen.

    ★肯定回答及否定回答Yes ， I have. / No ， I have not.

    ★特殊疑問句What have you done？

    What has he done？

    一般過去時與現(xiàn)在完成時的區(qū)別：凡是有明確的表示過去的時間狀語的句子
為過去時。

    注意：有些動詞表示的動作有一個終點，不能再延續(xù)，因此不能和表示一段
時間狀語連用。

    錯：I ‘ve left Beijing for 3 days. 對：I left Beijing 3 days ago.
I have been away from being for 3 days.