現在完成式

Δ 現在完成式：have / has + 過去分詞
用以表示截至現在為止與現在有關的動作或狀態。

（一）用以表示截至現在為止的動作的完成。
I have finished my work. 我已經完成我的工作了。
Have you eatem breakfast? 你吃過早餐了嗎？
-Yes, I have. -No, I haven't.
Has he read this book? 他讀過這本書了嗎？
-Yes, he has. -No, he hasn't.
He has gone to the United Atates. 他到美國去了。


（二）用以表示從過去繼續到現在的動作或狀態。
I have lived here for ten years. 我住在這裡十年了。
We have know him since ten yaers ago. 從十年前我們就認識他了。
John has been ill for two days. John生病兩天了。
He has eaten nothing since yesterday morning. 他從昨天早上到現在都沒吃東西。
We have studied English these two year. 這兩年我們學了英文。
How long have you been here? 你在這裡多久了？
I haven't seen her for a long time. 我好久沒見過她了。
He has lived there since he was born. 他從出生就住在這裡了。

（三）用以截至現在為止的經驗。
I have met him once. 我見過他一次。
He has visited me several times. 他拜訪過我幾次。
Have you ever seen a tiger? 你曾經見過老虎嗎？
-Yes, I have. -No, I haven't.
Have you ever been in Hong Kong before? 你以前曾經住過香港嗎？
-Yes, I have. -No, I've never been in Hong Kong.
Has he ever been to Japan? 他曾經住過日本嗎？
-Yes, he has often been to Japan. He has been there many times.