【日·课】只会用when…表达？太简单了！来学一个高级时间从句句型！
要表示时间，很多人会用when来引导时间从句，今天我们来学习一下“高级”时间从句句型：
By the time…, …
当……的时候……
说这个句型高级，除了因为使用了一个短语来引导之外，还有一个原因：使用这个句型时，主句中经常会用完成时！
为什么？因为“By the time”引导时间状语从句时，表示“到……的时候”，主句则表示在此时间之前某个事件已完成。一般来说，当从句用过去时时，主句通常要用过去完成时。
By the time…也可以表示未来发生的事，这时，从句使用一般现在时表示将来，而主句则通常使用将来完成时！
也可以根据具体情况，使用其他的时态。
来试试你能不能用这个句型讲出以下意思：
1) 当我到达火车站时，火车已经走了。
2) 当我们到达电影院时，电影都开始了。
3) 当我到达学校时，已经开始上课了。
4) 当医生到达时，病人已经死了。
5) 当我到达宴会时，人们已经准备离开了。
6) 到我回家那时，他们会已经离开了。
现在来对答案：
1) By the time I got to the station, the train had already gone.
2) By the time we got to the theater, the movie had already started.
3) By the time I arrived at school, the class had begun.
4) By the time the doctor arrived, the patient had already died.
5) By the time I got to the party, people were already leaving.
6) By the time I get home, they will have left.
全部说对的，Jessie老师给你100个表扬！你的英文相当不错哦！
没说对的也不怕，我们来实战练习：
1
A: By the time I got to the station, the train had already gone.
B: That’s too bad, but you are here now and that’s all that counts.
A：当我到达火车站时，火车已经走了。
B：那太糟了，不过你还是来了，这才是最重要的。
2
A: By the time we got to the theater, the movie had already started.
B: What a shame! The first five minutes of the movie are so exciting! You missed an important part of the movie!
A：当我们到达电影院时，电影都开始了。
B：真可惜！电影开头五分钟很激动人心！
3
A: By the time I arrived at school, the class had begun.
B: Did you get in trouble for being late? I hope not.
A：当我到达学校时，已经开始上课了。
B：你惹上麻烦了吗？我希望没有。
4
A: By the time the doctor arrived, the patient had already died.
B: Oh, I’m really sorry to hear that.
A：当医生到达时，病人已经死了。
B：噢，听到这消息真让人难过。
5
A: By the time I got to the party, people were already leaving.
B: Oh, that’s too bad, because I heard it was an excellent party.
A：当我到达宴会时，人们已经准备离开了。
B：噢，太糟糕了，因为我听说那是个很棒的宴会。
6
A: By the time I get home, they will have left.
B: Maybe you should hurry up and try to get back early. I know they are really looking forward to seeing you again.
A：到我回家时，他们会已经离开了。
B：也许你应该加快点，尽量早回家。我知道他们是很想再见到你的。
Now it's your time to open your mouth and follow me! 张开嘴巴跟着录音练起来！