请问by之后有什么用法

请问by之后有什么用法

很多种用法
（1）表示以一般的方法或方式.如：
No one in those days could live by writing poems.
（2）表示传达、传递的方式或煤介.如：
How did you send the letter,by airmail or by ordinary mail?
（3）表示用交通工具、通讯工具后接名词单数,不加冠词.如：
He came by train,but his wife came by bus.
注意下面两句的区别：
Did you come by train?
Did you come in his car / on my bike?
“by +抽象名词”构成的词组有：by accident / by chance / by diligence / by effort / by force / by heart / by luck / by mistake / by hard work.
将来完成时用来表示在将来某一时间以前已经完成或一直持续的动作.经常与before+将来时间或by+将来时间连用,也可与before或by the time引导的现在时的从句连用.
1) 构成will / be going to do sth.
2) 概念
a.状态完成：表示某事继续到将来某一时为止一直有的状态.
b.动作完成：表示将来某一时或另一个将来的动作之前,已经完成的动作或一获得的经验.
They will have been married for 20 years by then.
You will have reached Shanghai by this time tomorrow.将来完成时的构成
将来完成时的构成是由"shall/will + have +过去分词"构成的.
Before long he will have forgotten all about the matter.
不久他就会全然忘记这件事的.
He is somebody now.He will not have remembered his old classmates.
他现在是一个有身份的人了,他可能不会记得老同学了.
Will you have known Kevin for 10 years next month?
到下个月你认识凯文该有10年了吧?
将来完成时的用法
①表示在将来某一时间之前已完成的动作,并往往对将来某一时间产生影响.
We shall have learned 12 units by the end of this term.
到这个学期末,我们将学完12个单元.

by
prep.
1. 被,由
The homework was assigned by the teacher.
这些家庭作业是老师布置的。
2. 靠,用,通过
They crossed the river by ferry.
他们乘渡船过了河。
3. 经由;沿
Ellen flew to Chicago by way of Minneapolis.
艾伦经由明尼阿波利斯飞往芝加哥。
4. 在...旁边,靠近;在...手边
I haven't got any money by me.
我身边没有带钱。
5. 不迟于;在...之前
We had to get there by evening.
我们必须在夜晚前抵达那里。
6. 根据,按照
How do you know he didn't act by the rules?
你怎么知道他没有按规定行事?
7. (表程度)相差
He missed the bus by three minutes.
他晚了三分钟没赶上那班公车。
8. 凭,对...(发誓)
I swear by God!
我对上帝发誓!
9. (乘除法上)以...,用...(乘或除)
Nine divided by three makes three.
九除以三得三。
10. 以...计,按
You'll be paid by the hour.
你的工资将按时计酬。
11. 在...的时候
He had to sleep by day and work by night.
他只好白天睡觉,晚上工作。
12. 就...来说,关于
Philip is a doctor by profession.
菲利浦的职业是医生。
13. (表连续或反复)逐个;逐批
The teacher explained the text sentence by sentence.
教师逐句讲解了这篇课文。
14. 由于
She took my umbrella by mistake.
她误拿了我的伞。
ad.
1. 经过;过去
A truck went by.
一辆卡车开过。
2. 在旁边
When I filled out the form she was standing by all the time.
我填写表格时,她一直站在我身旁。
3. (放)在一边
They put money by for later use.
他们储存钱以备将来使用。
4. 【美】【口】到(或进入)某人的家
Please come by and have dinner with us.
请到我家来一起吃晚饭。

1）表示以一般的方法或方式.如：
No one in those days could live by writing poems.
（2）表示传达、传递的方式或煤介.如：
How did you send the letter,by airmail or by ordinary mail?
（3）表示用交通工具、通讯工具后接名词单数,不加冠词.如：
He came by train,but his wife came by bus.
注意下面两句的区别：
Did you come by train?
Did you come in his car / on my bike?
“by +抽象名词”构成的词组有：by accident / by chance / by diligence / by effort / by force / by heart / by luck / by mistake / by hard work.
将来完成时用来表示在将来某一时间以前已经完成或一直持续的动作.经常与before+将来时间或by+将来时间连用,也可与before或by the time引导的现在时的从句连用.
1) 构成will / be going to do sth.
2) 概念
a.状态完成：表示某事继续到将来某一时为止一直有的状态.
b.动作完成：表示将来某一时或另一个将来的动作之前,已经完成的动作或一获得的经验.
They will have been married for 20 years by then.
You will have reached Shanghai by this time tomorrow.
将来完成时的构成
将来完成时的构成是由"shall/will + have +过去分词"构成的.
Before long he will have forgotten all about the matter.
不久他就会全然忘记这件事的.
He is somebody now.He will not have remembered his old classmates.
他现在是一个有身份的人了,他可能不会记得老同学了.
Will you have known Kevin for 10 years next month?
到下个月你认识凯文该有10年了吧?
将来完成时的用法
①表示在将来某一时间之前已完成的动作,并往往对将来某一时间产生影响.
We shall have learned 12 units by the end of this term.
到这个学期末,我们将学完12个单元.
By the time you get home I will have cleaned the house from top to bottom.
你到家之前我将把房子彻底打扫一遍.

如以上回答内容为低俗、色情、不良、暴力、侵权、涉及违法等信息，可以点下面链接进行举报！

点此我要举报以上问答信息