本周，我们收到了中国的Candy的来信。Candy写道：
I wonder what is the difference between "not" and "no"? Today when I do my homework, I encounter the question. I do not know if it is "no need to do something" or "not need to do something" - Candy, China
我想知道not和no之间有什么区别？今天我在写作业的时候遇到了这个问题。我不知道应该是“no need to do something”还是“not need to do something”。—来自中国的Candy。
Dear Candy,
亲爱的Candy，
Thank you for writing to us. We do not usually answer homework questions, but I will try to explain the difference between the two expressions.
感谢你的来信。我们通常不回答作业上的问题，但是我将会尝试解释这两句短语之间的差异。
The word "not" is an adverb, which means it modifies – or changes the meaning of -- a verb. "Not" is often used with modal verbs, like "should," "can" and "might." Here are two examples.
Not这个单词是副词，表示它修饰或改变动词的含义。Not通常与情态动词配合使用，例如should、can和might。以下是两个例子：
You should not go to the park today.
你今天不应该去公园。
We might not have time to go before dark.
我们天黑前可能没时间去。
The phrase you saw, "not need to do something," looks like it is part of a sentence where "need" is used as a verb. Here are some examples.
你看到的短语“not need to do something”看起来是need用作动词的句子的一部分。以下是一些例子：
You do not need to clean the room.
你没必要打扫房间。
I have not walked the dog today.
我今天还没有遛狗。
They are not working on the project.
他们没在做这个项目。
In those sentences, "not" modifies the verbs clean, walk, and work. They show how "not" can be used as an adverb.
在这些句子中，not修饰clean、walk和work这些动词。它们展示了not如何被用做副词。
The word "no" can be used as an adverb, adjective, or noun. In your sentence, "There is no need to do something," "no" is used as an adjective, modifying the noun "need." The verb in that sentence is a form of the word be: "is."
No这个单词可以用做副词、形容词和名词。在你说提到的“There is no need to do something”这句话中，no被用做形容词，修饰need这个名词。这句话中的动词是be动词is。
Here are examples of "no" being used as an adjective:
以下是no被用作形容词的一些例句：
The store has no eggs on the shelf.
商店的货架上没有鸡蛋。
People with no internet connection at home can go to a library.
家里没有网络的人们可以去图书馆上网。
"No" is also often used as an adverb. For example, your parents may have told you,
No通常还用作副词。例如，你的父母可能跟你说过，
No, you cannot have any more candy.
不，你不能再吃糖了。
In that sentence, "no" answers the question, "Can I have more candy?" I am wondering if that is where you got your nickname, Candy.
在这句话中，no回答的是“Can I have more candy？”这个问题。我好奇这是不是你的昵称Candy的出处。
By the way, I hope you have "no problems" with doing your homework now.
顺便说一句，希望你现在在做作业上没有问题啦。
What question do you have about American English? Send us an email at learningenglish@voanews.com.
你对美式英语有什么疑问呢？给我们发邮件来提问吧。
And that's Ask a Teacher for this week.
以上就是本期名师答疑的全部内容。
I'm Jill Robbins.
我是吉尔·罗宾斯。(51VOA.COM原创翻译，禁止转载，违者必究！)