Why you don't ... Why don't you... which is the difference?

[SunMoon]

Is any difference between these two questions:

Why you don't come with me?

and

Why don't you come with me?

I assume that in the first one, I already know that he doesn't come with me and I am just asking why.

In the second one, I do not why and even I don't know that he is not coming.

 

[emsr2d2]

Is any difference between these two questions:

Why you don't come with me?

and

Why don't you come with me?

I assume that in the first one, I already know that he doesn't come with me and I am just asking why.

In the second one, I do not why and even I don't know that he is not coming.

The first is grammatically incorrect. You cannot say "Why you don't come with me?" You would say "Why won't you come with me?" or "Why are you not coming with me?"

"Why don't you come with me?" is a suggestion. You are basically asking someone if they would like to come with you, but you don't yet know what the answer will be.

If they say no, then you would use "Why aren't you coming?" or "Why won't you come?"

 

[PROESL]

Is any difference between these two questions:

Why you don't come with me?

and

Why don't you come with me?

I assume that in the first one, I already know that he doesn't come with me and I am just asking why.

In the second one, I do not why and even I don't know that he is not coming.

Emsr2d2 provided a great answer. It's spot-on. However, I would like to add something.

Why you don't come with me? This is wrong because the negative auxiliary "don't" must precede the subject "you". Auxiliaries precede subjects in interrogative sentences.

Why don't you come with me? This is correct, and "don't", the auxiliary, comes before "you", the subject.

The clause "why you don't come with me" is only correct as part of another sentence, or functioning as a dependent clause. In this case it would be a noun clause.

Here's how it works: I don't know why you don't come with me.

The clause "why you don't come with me" is the object of the verb "know". It tells us what the speaker does not know.

Sincerely,