All it needs is a question mark. Have you had lunch? That is grammatically correct.
Yes.
The correct form of invitation in "you are invited to lunch" or "you are invited at lunch" is "you are invited to lunch". You could also say, "you are invited to lunch at my house" as this would be grammatically correct.
Yes the question What do you eat for lunch? is grammatically correct.This is something you would ask someone to find out what types of things they usually eat for their lunch.Not to be confused with What did you eat for your lunch?which is a question to find out what someone had at a specific time for their lunch.
No, it should read "Will you have a potluck lunch here, pending reservations?"
The grammatically correct statement is "She does not have her book." In English, the verb "have" is used as an auxiliary verb in negative sentences, so the correct form is "have" instead of "has."
"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'.
'What a drunkard you are' is a grammatically correct English sentence.
Yes, Almighty God is grammatically correct.