When good is used as a noun, no can quantify or modify it. For example, “No good can come from this evil plan,” or “His suspicious behavior indicated that he was up to no good.” 

Good在这里的词性是名词，no则用来量化它或修饰它。比如说，“这个邪恶的计划没有好处（只能带来no good）”，或者“他可疑的行为表明了他不怀好意（打算做no good的事）。”

In these sentences, we can’t really use not in place of no because both nos refer to a quantity of zero good. 

在这些句子中，我们不能用not代替no，因为两个no都表示good的数量是零，无。

Some writers connect no and good with a hyphen when it’s used as an adjective phrase that’s connected to a noun (e.g. “The no-good dishwasher stopped working again,”).

有些作家在把no和good用作形容词词组和名词连用时，会用连字符把它连接起来(例如：没用的洗碗机又停止工作了)。

No good is an adjective phrase when good modifies a noun and no indicates the degree to which good applies.

当no good是一个形容词短语时，good修饰名词，no表示good的适用程度。

No good is the complete absence of good. It means something is of no use or value for anything or to anyone.

No good就是完全没有好的成分。它的意思是某物对任何事物或任何人都没有用处或价值

It can refer to a person, as in, “Jack was always in trouble. He was just no good.” It can describe something as useless or worthless, as in, “The spare tire is no good. It has a hole in it.” 

它可以指一个人，例如，“杰克总是惹麻烦。那么他就是no good”。它可以形容某物无用或无价值，如：“备用轮胎no good。它有一个洞。”

It can also describe something that’s gone bad or lost its effectiveness, as in, “This milk is no good. It expired last week.”

它也可以用来描述某物变坏了或失去了效用，如：“这牛奶是no good（不能喝）的。它上周过期了。”

Not good is used strictly as an adjective. Not acts to disqualify something from being good. It implies that something is either bad or mediocre. 

Not good仅作为形容词使用。not使某物失去成为好的资格。它暗指某物不好或平庸

It’s used as an adjective to describe the condition or state of something, as in, “Chocolate is not good for dogs.” It can’t be used as a noun.

它用作形容词来描述一种状态或条件，比如“巧克力对狗not good（不是好的作用）。”它不可以当做名词来使用。

Not good means something has (or once had) the potential to be good, but isn’t. For example, “That dinner was not good,” implies that particular meal tasted bad.

Not good的意思是某物有(或曾经有)变好的潜力，但是现在却不是。例如，“That dinner was not good的意思是某顿饭很难吃（本可以好吃的）。”

Saying “That dinner was no good,” can imply that there wasn’t a single good part of the meal or that it didn’t satisfy the speaker’s hunger.

而如果说“晚餐no good”，就意味着晚餐中没有一个好的部分，或者不能解决说话者的饥饿。

Not good also can imply that a situation hasn’t reached a conclusion. “Mary’s chances of finishing the race after twisting her ankle are not good,” means that there’s very little possibility of Mary finishing her race. There may be some sliver of hope, but not much.

“Not good”也可以指情况还没有得出结论。“玛丽扭伤脚踝后完成比赛是not good的”，这意味着玛丽完成比赛的可能性很小。可能会有一线希望，但不是很多。

If we said “Mary’s chances of finishing the race are no good,” it would mean it’s impossible.

如果我们说“玛丽完成比赛是no good”，那就意味着这件事就是根本不可能的。