With examples from Burn Notice, Psych, and Due South.
Deciding when to use either versus neither can be confusing. Either is used to show that you are choosing between two possibilities. So if you are choosing between one option or another option, use either.
The bomb could have killed either one of them; it was only sheer dumb luck that Ray Kowalski was still standing and the perp was dead.
It can also be used following negative statements as an intensive, to give emphasis to the statement.
“Fine,” Shawn Spencer said, “if you’re not talking to me, I’m not talking to you, either.”
If you are having trouble deciding whether to use a singular or a plural verb, look to the word that immediately follows. If it is singular, your verb should be singular. If it is plural, your verb should be plural. This also applies to neither.
Fi held up two dresses. “Which should I wear tonight?” Michael Weston shrugged. “Either one looks fine to me, Fi.”
Neither is used when refusing both of the two options. (Remember, if you are referring to three or more options, use none.)
“They saw us, Fi, they know what we look like,” Michael said, frustrated. Neither of them was going to be able to sneak in now.
Henry Spencer glared at Shawn and Gus. “Neither of you thought to bring any backup?”
Fraser didn’t like the plan, and neither did Ray.
Either is often used in conjunction with or.
Sam was tired of waiting. “Look, either you can come out nicely, or I can come in there with my very large gun.”
Shawn looked over the ice cream counter. “Gus, we’ve only got two options: either peanut butter brittle, or pineapple surprise. I’m leaning toward the surprise.”
Ray crossed his arms. “Either you come straight with me or I’m leaving, Fraser. Were you or were you not just conversing with yourself in the closet?”
Neither is often used in conjunction with nor. (If you are confused as to whether you should be using or or nor, remember that neither and nor both start with n. It always works for me!)
Neither Sam nor Fiona had heard from Michael all day. They were starting to get worried.
Shawn was proud of the witnesses he'd found, but Gus was unimpressed. They were neither particularly polite, nor scrupulously clean.
Fraser rolled his eyes at his half-wolf. “Neither Ray nor I had any donuts, Dief. We were merely at the bakery to question suspects."