If you use either at the end of sentence should comma in front it?

You don't need a comma before "either" at the end of a sentence unless it's part of a parenthetical phrase.

Here's why:

* "Either" as a pronoun: When "either" acts as a pronoun, it usually replaces a previous noun or phrase. It doesn't need a comma.

* Example: "Would you like tea or coffee? I'll have either."

* "Either" as part of a correlative conjunction: When "either" is paired with "or" or "neither...nor," it doesn't need a comma.

* Example: "I'm not sure if I want to go to the beach or stay home, either."

* "Either" in a parenthetical phrase: If "either" is part of a phrase that's not essential to the main sentence, it can be set off with commas.

* Example: "I'm going to the store, either today or tomorrow."

In summary: You typically don't need a comma before "either" at the end of a sentence unless it's part of a parenthetical phrase.