(单词翻译:单击)
If you can write or speak even just a little English, you have surely used prepositions -- words like "to," "in," "on," "at" and "by".
如果你会写或说一点英语，你肯定用过像“to”、“in”、“on”、“at”和“by”这样的介词。
A preposition is a word or group of words that shows direction, location or time.
介词是表示方向、地点或时间的一个词或一组词。
Today on Ask a Teacher, we have a question about one such word.
今天在名师答疑节目中，我们有一个关于介词的问题。
Hi, I'm Frank John from Tanzania.
嗨，我是来自坦桑尼亚的Frank John。
I don't how know to use "by" in a sentence.
我不知道如何在句子中用“by”。
Hello Frank!
你好，弗兰克！
It sounds like you know the meaning of "by" but are unsure of how to use it with other words.
听起来你知道“by”的意思，但不确定如何与其他单词一起使用。
Let me try to help!
让我来帮你吧！
"By" is usually a preposition but sometimes acts as an adverb.
“by”通常用作介词，但有时用作副词。
It can be used in many ways, but today we will talk about four uses as a preposition and show you where it is placed in a sentence.
它有很多用法，今天我们将讨论“by”做介词的四种用法，并告诉你它在句子中的位置。
Let's start with using "by" to show place or location.
让我们从“by”来表示地点或位置开始。
When we use "by" this way, it means "close to" "next to" or "beside" .
当“by”表示地点和位置时，意思是“靠近”、“紧挨着”或“在……旁边”。
Here are two examples.
请听两个例子。
Note that "by" comes before the place.
请注意，“by”放在地点名词之前。
Meet me at the show! I'll be seated by the door.
演出现场见！我将坐在门边。
The university is by the sea.
那所大学在海边。
Now for the second use.
现在是第二种用法。
When "by" is placed after motion-related verbs — like "run," "drive," and "walk" — it often shows movement past a place.
当“by”放在与运动有关的动词之后时——如“run”、“drive”和“walk”通常表示运动经过一个地方。
Let's listen: I walked by the river on Sunday. It was a beautiful day!
让我们听一下：星期天我在河边散步。那是美好的一天！
Did you drive by my building today? I thought I saw you.
你今天开车路过我家了吗？我想我看到你了。
Another way we use "by" is to talk about time on a clock.
“by”的另一个用法是谈论时钟上的时间。
When we use it this way, it means "not later than."
用作这种含义的时候，它的意思是“不迟于。
The word "by" comes before the time.
“by”这个词出现在时间之前。
Have a listen: Your appointment is at 1:00. Please arrive by 12:45.
请听示例：你的约会是在1点。请在12点45分之前到达。
We should leave by 7:00 to beat the crowds.
我们应该在7点前离开，以免人潮拥挤。
The last use we will consider today is about doing something alone or without any help.
今天我们要探讨的by最后一个用法是“独自或无需任何帮助做某事”。
We make this meaning with "by" followed with a reflexive pronoun, such as "myself" or "yourself."
我们用“by”后接反身代词来表达这个意思，比如“我自己”或“你自己”。
Here are two examples: He moved the heavy table all by himself.
这里有两个例子：他一个人搬了那张沉重的桌子。
I'm sorry, I couldn't go. Did you go by yourself?
对不起，我不能去。你一个人去的吗？
And that's Ask a Teacher.
以上就是今日名师答疑的全部内容。
I'm Alice Bryant.
我是艾莉丝·布莱恩特。
