你知道by的用法吗?快来一起学习吧，下面小编就和大家分享，来欣赏一下吧。
by的各种用法详解
by表单位的用法归纳
表示单位，意为“以……计”，其后通常接表示计量单位的单数名词，且名词前要用定冠词。如：
They are paid by the hour (by the month). 他们所得报酬按小时(月)计。
Milk is sold by the pint, butter by the pound, and eggs by the dozen. 牛奶按品脱卖，黄油论磅卖，蛋类论打卖。
有时也接抽象名词，此时通常不用冠词。如：
Bananas are usually sold by weight. 香蕉通常按重量卖。
by表示时间的用法
表示时间，指“最迟在……之前”“到……的时候已经”，此时要注意它所连用的时态。如：
He was very tired by the evening. 他到晚上已经很累了。
He has read about 40 pages of the book by now. 现在这本书他已读了大约40页。
We will have finished the work by next month. 到下个月我们就会干完了这工作。
By the time the doctor arrived the patient had died. 在医生到达时，病人已经死了。
另外，表示时间时，它还可表示“在……期间”，通常连用的名词是 day, night, moonlight, daylight等，注意名词前通常不用冠词。如：
Cats sleep by day and hunt by night. 猫白天睡觉，夜里捉老鼠。
Do you like to swim by moonlight? 你喜欢在月光下游泳吗?
表示手段或方式等，注意以下用法：
(1) 表示“乘”“坐”时，其后接交通工具(如 bus, bike, train, plane, car, taxi, ship等)或与交通工具密切相关的名词(如air, water, land, road等)，在句中主要用作方式状语，其中通常不用冠词或其他限定词。如：
They came here by the first bus. 他们是坐第一班车来的。
但是，若表示交通工具的名词前插有定语修饰语，则也可以用冠词。如：
We’re going by the 9:30 train. 我们坐9:30的火车去。
We went to Shanghai by a large ship. 我们乘一艘大船去上海。
注意，汉语说“步行”，英语习惯上用on foot, 而不用 by foot。
(2) 注意以下表示方式的有用表达，其中不用冠词或其他限定词：
by phone 用电话 by telegram 用电报
by letter 用信件 by express 用快件
by air mail 用航空邮件 by ordinary mail 用平信
by post 用邮寄 by radio 用无线电
by hand 用手工 by machine 用机器
注意下面两例用by与用with的区别：
The letter was written by hand. 这封信是用手写的(即不是打印的)。(by hand表示一种抽象的手段，是无形的，注意其中没用冠词或其他限定词)
I write with my hand, but he writes with his mouth. 我用手写字，但他却用嘴写字。(with one’s hand表示一种具体的工具，是有形的，注意其中用了物主代词)
(3) 后接动名词表示行为的方式或手段，这是一种常用表达。如：
He makes a living by teaching. 他以教书为生。
Lock this door by turning the key twice to the left. 锁这扇门要把钥匙向左转两圈。
By 的基本用法
英语介词是让我们英语学习者感觉最为头疼的部分，虽然介绍本身都非常简单易学，但介绍的用法却非常复杂，不易掌握，每个介词都有不同的用法，下面简单介绍一些BY的一些基本用法：
第一种：被动语态中(被 由)
She was hit by a truck.他被一个卡车撞倒了。
A painting by Van Gogh has been sold in New York for more than eighty-two million dollars.
一幅由梵高创作的画在纽约卖到超过八千二百万美元。
第二种：通过 使用
Teachers live by selling knowledge.
老师通过知识谋生。
第三种：在……之前 不迟于
It needs to be ready by next fridy
下周五之前准备好。
第四种：靠近 在……旁边
She stood by the window 他站在窗户旁边
come and sit by me. 来坐在我旁边。
第五种：路过 经过
He walked right by me without even saying hello.
他从我身边路过，甚至连招呼都没打。
I pass by the school every day on my way to work.
我每天上班的路上会经过这所学校。
第六种：逐渐的变化
Day by day , she grew weaker.
一天比一天虚弱。
第七种：抓着(物体或者身体)
By the arm
抓着(搀扶)着胳膊。
第八种：By oneself 单独 独自一个
He spent christmas all by himself
他自己度过的圣诞节。
第九种：乘以 除以
What is 36 divided by 4?
36除以4是多少?
第十种：(用于短语中)由于 出于
I met him by chance out walking yesterday.
我昨天外出散步偶然遇到了他。
英语语法专项之介词 by的14种用法
1. by+交通工具。
表示凭借、乘坐某种交通工具，在句中作方式状语。如：by car, by plane, by bike 等。
eg. She went to Beijing by air.
2. by +doing sth.
意为"通过做某事”，表示方式、方法、手段等，在句中做方式状语。
【经典考题】
You can improve your English ___B___practicing more.
A. by B. with C. of D. in
注意：对by引导的介词短语作方式状语， 提问时用how。
—— How do you study for a test?
—— By listeningto tapes.
3. (表示位置)在……近旁;在身边;靠近。
eg. On a cold evening，It is pleasant to sit bythe fire.
4. (表示时间)不迟于，在什么之前。
eg. Be here by four o'clock. (4:00之前到这儿。)
【经典考题】
How many English songs had you learned___A___ the end of last term?
A. by B. with C. at D. in
解析：by the end of last term, 译为”到上个学期末“。
5. 表示方向，从……中经过。
eg. They came in bythe back door. ( 他们是从后门进来的。)
6. 做介词， 译为“经过”。
eg. He walked by me without speaking. (他走过我的身边，没有说话。)
7. 用在反身代词之前，译为“独自”。
eg. Sarah couldn't move the heavy box by herself.。
8. 表示动作的执行者，用于被动语态，译为：”被，由“。
eg. The glasses are usedby us.
9. 表示“根据“，“按照”的意思。
eg. What time is it by your watch? (你的表几点了?)
10. 和take，hold等动词连用，说明接触身体的某一部分。
eg.I took him by the hand。(我拉住了他的手。)
11.(乘或除)以。
4 divided by 2 is 2. (4除以2等于2)。
12. 表示幅度。
Violent crime has increased by10 percent since last year.( 暴力犯罪自去年以来增加了10%。)
13、以…计;按…计。Billing isby the minute. (以分钟计账。)
14. 用于一些固定短语中， 如：
by the way 顺便问;one by one 一个接一个的;step by step 一步步地;day by day 一天接一天地;by accident 偶然地…
By的用法很多，但其实很多意思可以整合起来记忆，希望通过整理，对大家学习“by"的知识有些帮助。
说说“by”的用法
by |baɪ|
prep. adv.
1. near sb/sth; at the side of sb/sth; beside sb/sth 靠近;在…旁边
a house by the river
河边的一所房子
The telephone is by the window.
电话在窗户旁边。
Come and sit by me.
过来挨着我坐。
2. used, usually after a passive verb, to show who or what does, creates or causes sth (常置于表示被动的动词后，表示使为者)
He was knocked down by a bus.
他被公共汽车撞倒了。
a play by Ibsen
易卜生写的剧本
Who's that book by?
谁是那本书的作者?
I was frightened by the noise.
我被那响声吓坏了。
3. used for showing how or in what way sth is done (表示方式)
The house is heated by gas.
这房子是煤气供暖的。
May I pay by cheque?
我能用支票付款吗?
I will contact you by letter.
我会给你写信联系的。
to travel by boat/bus/car/plane
乘船 / 公共汽车 / 轿车 / 飞机
to travel by air/land/sea
坐飞机;经陆路 / 海路
Switch it on by pressing this button.
按下这个开关启动它。
4. used before particular nouns without the , to say that sth happens as a result of sth (置于不带the的名词前，表示原因)由于
They met by chance.
他们不期而遇。
I did it by mistake.
我误做了这事。
The coroner's verdict was ‘death by misadventure ’.
验尸官判定是“意外致死”。
5. not later than the time mentioned; before 不迟于;在…之前
Can you finish the work by five o'clock?
你五点钟前能完成工作吗?
I'll have it done by tomorrow.
我将于明天之前让人做完这件事。
By this time next week we'll be in New York.
下星期的这个时候我们将在纽约。
He ought to have arrived by now/by this time .
他现在应该已经到了。
By the time (that) this letter reaches you I will have left the country.
你收到这封信时，我已离开这个国家了。
6. past sb/sth 经过
He walked by me without speaking.
他一言不发地从我身边走过。
7. during sth; in a particular situation 在…期间;处于某种状况
to travel by day/night
白天 / 夜间旅行
We had to work by candlelight.
我们不得不借助烛光工作。
8. used to show the degree or amount of sth (表示程度、数量)
The bullet missed him by two inches.
子弹只差两英寸就击中他了。
House prices went up by 10%.
房价上涨了10%。
It would be better by far (= much better) to…
那比…好得多。
9. from what sth shows or says; according to sth 从…看;依;按照
By my watch it is two o'clock.
我的表是两点钟。
I could tell by the look on her face that something terrible had happened.
从她的脸色我可以看出，发生了可怕的事情。
By law, you are a child until you are 18.
按照法律规定，18岁之前是未成年人。
10. used to show the part of sb/sth that sb touches, holds, etc. (表示触及或抓住的人或物的部分)
I took him by the hand.
我拉着他的手。
She seized her by the hair.
她揪住她的头发。
Pick it up by the handle!
抓着手柄把它提起来!
11. used with the to show the period or quantity used for buying, selling or measuring sth (与the连用，表示时间或量度单位)
We rented the car by the day.
我们按日租用汽车。
They're paid by the hour.
他们的报酬是按小时计算的。
We only sell it by the metre.
我们只按米出售。
12. used to state the rate at which sth happens (表示速率)
They're improving day by day.
他们在一天天地改进。
We'll do it bit by bit.
我们会一点一点地做。
It was getting worse by the minute (= very fast) .
情况急速恶化。
The children came in two by two (= in groups of two) .
孩子们一对一对地走了进来。
13. used for giving more information about where sb comes from, what sb does, etc. (补充有关出生地、职业等的信息)
He's German by birth.
他是德国血统的。
They're both doctors by profession.
他们两人的职业都是医生。
14. used when swearing to mean ‘in the name of ’ (起誓时用)以…的名义
I swear by Almighty God…
我以全能上帝之名发誓…
15. used to show the measurements of sth (表示尺寸时用)
The room measures fifteen feet by twenty feet.
房间15英尺宽20英尺长。
16. used when multiplying or dividing (用于乘除运算)
6 multiplied by 2 equals 12.
6乘以2等于12。
6 divided by 2 equals 3.
6除以2等于3。
习语
by the by/bye
= by the way at way n
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