No.
This is singular, is is the singular form of the verb be, a is an indefinite article used before singular nouns, but shoes is plural.
"This is a black shoe" is correct.
"These are black shoes" is correct, as well.
It is grammatically correct as a question.
No, it is not grammatically correct to say "a pair of clothes." The correct phrase is "a pair of pants" or "a pair of shoes" because these items come in pairs. "Clothes" is a plural noun.
It is grammatically correct to say: There is nothing wrong with this machine.It is not grammatically correct to say: Will it is be grammatically correct to say ....The correct way to write that or say that would be: Would it be grammatically correct to say....
Correct
No. The indefinite article "a" comes before singular nouns, and "shoes" is plural. In the right context, you could use "the". Example: These are the black shoes that I've always wanted. Depending on the sentence, you might not need an article at all. Example: I need black shoes to go with my dress.
"Not like that" can be grammatically correct, depending on the context.
Yes! That is grammatically correct!
Yes, 'for free', is grammatically correct.
The phrase "You are not knowing" is not grammatically correct. Instead, you can use "You do not know" or "You are not aware."
Yes, Almighty God is grammatically correct.
"That was wrong" is a grammatically correct sentence.
Yes, it is grammatically correct.