Yes it is correct, but in text is should be written 'a thousand organizations'. Either is correct however:
We have a 1000 organizations on our mailing list.
We have a thousand organizations on our mailing list.
"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.
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.
'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.