Is this a correct use of dont, and auquel?

Question

I wanted to ask if my following answers are correct

Je sais pas dont je parle

Means "I don't know what I'm talking about" right? And if you say

Je sais pas ce que j'en parle

Means "I don't know what I talk of it"

And

Je sais pas auquel je pense

Means "I don't know what I'm thinking"

And

Je sais pas ce que j'y pense

Means "I don't know what I think of it" Right?

Answer 1

"Je sais pas dont je parle" is not possible, because "dont" is a relative pronoun referring to a noun that is a complement of the preceding proposition, and here you have omitted it. Moreover, "pas" is not really a negation: it has to be used with "ne". You should say:

"Je ne sais pas de quoi je parle" or "Je ne connais pas ce dont je parle"

Then "Je sais pas ce que j'en parle" is wrong as well

Here, you could say:

"Je ne sais pas ce que j'en dis" (I don't know what I say about it)

This is correct, although the meaning is rather queer. You cannot say "ce que j'en parle" because parler is not a transitive verb, meanwhile "dire" is transitive..

Bad luck once more,

"Je sais pas auquel je pense"

is wrong also. "auquel" like "dont" refers to a complement of the preceding proposition, but with the sens of "to that" meanwhile "dont" means "of that". But in your sentence, you have no referring complement, so you should say:

"Je ne sais pas à quoi je pense".

"Je sais pas ce que j'y pense"

is wrong, although the motto of the English kings is "honi soit qui mal y pense", but this is old French from the middle-age. Here, you cannot say "y" be cause "y" means "to that", which has no sense here, where you mean "about that", so you must use "en". The correct form would be:

"Je ne sais pas ce que j'en pense".