“作業沒寫完，就不能吃飯！”這句話，你小時候聽過嗎？蟲子小時候，蟲蟲媽就像一臺復讀機：“你寫完作業沒有？”
寫作業，影響到今晚吃飯的大事：這種“影響”，就是這節課要講的「現在完成時」。
01. 意義：9個字
02. 結構
從上面3個例句，可見現在完成時的結構：
用 have 還是 has，就看主語是單數還是複數。原則是保持：主謂一致。
下面，根據提示，將下列句子變為現在完成時。
1）We ____________ (discuss) this issue a few times.
2）Tom and Jerry ____________(know) each other since they were at primary school.
3）Dad ____________(just take) the medicine.
4）She ____________(not hear) from him.
5）________ you ____________(see) Tony today?
03. 常用時間狀語及其位置
>> 對比 for 和 since 的用法
【for + 一段時間】指持續了一段時間。
【since + 過去的時間點/ 過去的事件】指從過去的某個時間點，一直延續到現在。
注：ago“多久之前”，只能用於一般過去時。
>> already/ just/ still/ yet 的位置
觀察例句，總結規律：
>> 現在完成時不與過去的具體時間連用
體會一下：
☑️ I have walked the dog.
我遛過狗子了。
可以表示：你不用再遛啦
❌ I have walked the dog yesterday.
昨天我已經遛過狗子？？？
1）表示過去某個時間發生的事情，只能用「一般過去時」：
I walked the dog yesterday.
我昨天遛了狗子。（僅僅表達昨天·我·遛狗這件事，和現在沒有關係）
2）如果是未完成的時間，比如 today，this year，this month，this week 這類，可以用「現在完成時」。
I have walked the dog twice today.
今天我遛了狗子兩次。（today 是還沒有結束的時間，用 have done 表示“已完成”）
04. 難點
1）have been & have gone
have been“去過”
have gone“已經去了，還沒有回來”
>> Tony has been to Japan twice.
託尼去過日本兩次。（可能是去拜師學藝）
>> Tony has gone to Japan.
託尼已經去日本了。（下次再來剪頭，託尼這會不在呢！）
>> Where have you been?
你去哪兒了？（你已經回來）
>> Where have you gone?
你去哪兒了？（你不在身邊）
2）短暫性動作 → 持續性動作
在「狀語從句」這節課中，蟲子提到過這2個概念：“
短暫性動作，就是很短暫的、一瞬間就結束的動作，不能持續下去。比如起床 get up，眼睛一睜，起床的動作就完成了；再比如 die，斷氣的一瞬間就死透了。相反，可以延續的動作，比如你可以不帶喘氣地打3小時王者、跑5公里路、寫8000字論文、睡到第二天下午…… 這些 play, run, write, sleep 等動作，就是持續性動作。
在現在完成時中，短暫性動詞不能跟表示一段時間的狀語連用（因為短）：
❌ Tony has arrived in Japan for a few days.
下飛機那刻就算到了，不跟 for…連用。
❌ The woman has left since her husband was sent to prison.
跑路也就是買個票走人的事情，短暫性動作，不跟since…連用。
❌ My rabbit has died for a week.
die 指斷氣的那一瞬間，不跟for…連用。
表示一段時間的狀態，必須用持續性的動作。所以，上面的句子應該改為：
在現在完成時裡，短暫性動詞 → 延續性動詞，有幾組常用的，必須背的啊：
arrive → have been here
die → have been dead
leave → have been away
finish → have been over
borrow → have kept
buy → have had
獲取完整版《短暫性動詞 → 延續性動詞表》
微·信·公·號：蟲蟲講英語
後·臺·回·復：現在完成時
05. 課後練習
提醒：現在完成時、一般過去時均有。建議拿出紙筆寫下答案，做完後統一對答案。
Mary Morris ____________(apply) for her passport last month because she will soon be leaving on a trip that she ____________ (dream) about for many years. She ____________(work) as a receptionist at Ardmore's Travel Agency for ten years. All this time, she has been looking at pictures of exotic places on the wall and planning trips for others. For this reason she ____________(decide) to take an overseas trip herself.
After she ____________(plan) her trip, she ____________(make) her plane flights and ____________(reserve) hotel rooms. Mary doesn’t have to pay for her plane tickets because she ____________(work) at the travel agency for so long.
She ____________(want) take this trip for a long time, but each year her boss ____________(cancel) her vacation because someone else ____________(be) on vacation or someone ____________(quit).
Mary ____________(hear) about many exciting vacations over the years. Her boss, Ben, ____________(go) to Japan, Kenya, Alaska, France and Moscow last year. Meanwhile, Mary ____________(only see) these exciting places in photos! After looking at her boss' travel pictures, Mary ____________(decide) to take a trip of her own.
題目來源： grammar-quizzes
獲取答案方式
微·信·公·號：蟲蟲講英語
後·臺·回·復：現在完成時
「蟲蟲講英語」老少咸宜的英語學習號 —— 有時候，語法換一種方式講，就聽懂了。
06. 總結：
意義：9個字——已發生、持續性、影響性
結構：have/ has done
常用時間狀語：
易混淆：have been“去過”；have gone“已經去了，還沒回”
短暫性動作 → 持續性動作：
arrive → have been here
die → have been dead
leave → have been away
finish → have been over
borrow → have kept
buy → have had
呼，I have finished my homework! 終於可以開飯了，拜！
