"Not like that" can be grammatically correct, depending on the context.
Yes it is a grammatically correct
Yes! That is grammatically correct!
Yes, 'for free', is grammatically correct.
This is not grammatically correct. The correct form is 'you do not know', or the abbreviated 'you don't know'.
Yes, Almighty God is grammatically correct.
"That was wrong" is a grammatically correct sentence.
Yes, it is grammatically correct.
'Rhoda's crazy' is grammatically correct.
'What a drunkard you are' is a grammatically correct English sentence.
"For free' is grammatically correct. It is an idiom of the English language.
The sentence is grammatically correct.