"On a date" is correct when talking about going out with someone. You would say "Tom is going on a date with Betty," not "Tom is going in a date with Betty."
"In a date" would be used when talking about the fruit date and something inside of the date. "There are seeds in the date," or "Molly put goat cheese in the date."
"That was wrong" is a grammatically correct sentence.
Yes, it is grammatically correct.
Yes, Almighty God is grammatically correct.
This sentence is grammatically correct.
This sentence is not grammatically correct. For the sentence to be grammatically correct, the space between "in" and "to" would have to be removed. Therefore the sentence should read "They are into skating."
Both "which date" and "what date" are grammatically correct. You can use either one depending on your personal preference or the context of the sentence.
Yes, it is grammatically correct to say "this date and time is good for me" when referring to a specific date and time that works for you.
Yes, 'for free', is grammatically correct.
"Not like that" can be grammatically correct, depending on the context.
Yes! That is grammatically correct!
Yes, it is grammatically correct to abbreviate "March" as "Mar." for a date, such as Mar. 15th. Just be sure to use the period after the abbreviation to show it is shortened.
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.
"That was wrong" is a grammatically correct sentence.
Yes, it is grammatically correct.
Yes, Almighty God is grammatically correct.
Sure. It would also be grammatically correct to write He spoggled his nubbix on the goober. Grammatically correct and meaningful are not the same.