Yes
The sentence "There are five pens in the box" is grammatically correct.
Gramatically, the phrase "a box of candles" is correct. Also, if you had more than one box, you would say "boxes of candles."
"Not like that" can be grammatically correct, depending on the context.
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'.
Sure. It would also be grammatically correct to write He spoggled his nubbix on the goober. Grammatically correct and meaningful are not the same.
'What a drunkard you are' is a grammatically correct English sentence.
"That was wrong" is a grammatically correct sentence.
Yes, Almighty God is grammatically correct.
Yes, it is grammatically correct.
The phrase "the box of blocks was dropped" is grammatically correct. It indicates that the box, which contains blocks, was the subject that experienced the action of being dropped. The sentence is clear and correctly uses the passive voice.