"Who sells it?" is correct (always capitalize the first letter of a sentence).
Yes, "He sells cars" is correct.
Honda Motors sells cars. correct with a period at the end :)
From 8:00 a.m. until 6:00 p.m., Mr. Downs sells hardware.
"How are you" is a correct sentence.
Yes, this sentence is correct.
You are palpitating. This is a correct sentence.
With the exception of not capitalizing the 'y' at the start of the sentence, it is a correct sentence.
That sentence is grammatically correct.
no it is not a correct sentence.
no_____If the sentence is You do do that (meaning You are in the habit of doing that) the grammar is perfectly correct and the sentence 'does have correct grammar'.
From 8:00 a.m. until 6:00 p.m., Mr. Downs sells hardware. add a colon between 6 and 00
"You and him" is correct in a sentence such as, "I sent the tickets to you and him," versus a sentence such as, "You and he should send the tickets to me."