現在完成式 (Present Perfect Tense)
I have done my homework.
過去的某個動作，不久前才剛剛完成 (... just...)。
I have just done my homework.
Have you ever eaten snake?
How long have you lived here?
Since when have you been sick?
Cindy has always loved shopping.
帶有 since 或 for 表時間的介系詞，通常用現在完成時式。for 表示一段時間， since 表示從過去某一時間點到現在。
Rebecca has lived here for 10 years.
Rebecca has lived here since 2001.
I have been here for two hours.
I have been here since 10 o'clock.
Mr. Yang has worked in this factory _______ 1968.
(A) since (B) before (C) for (D) in
Tina is getting married to a man she has known only _______ a month.
(A) for (B) on (C) in (D) since
帶有副詞 ever, never, still, just, already, yet 等的句子，通常需要用現在完成式或過去完成式。
Have you ever failed a class?
She has never been to Korea.
Mary has just finished her homework.
Don't forget to tell him to be here on time. ～
I have already told him.
Have you done your homework? ～
No, I haven't done it yet.
The idea of this great movie comes from a novel which has _______ been read and loved by many people.
(A) still (B) just (C) ever (D) already
"been to" 與 "gone to" 用法不同
He has been to Japan.
Have you ever been to Japan?
Yes, I went to Tokyo last month.
He has gone to Japan.
Is Andy in Japan?
Yes, he's gone to Japan. He'll be back next month.
he's = he has; he'll = he will