Grammar: Both either and neither

The words either, neither, and both are all used to talk about how two objects relate to each other.

• “Either” means “X OR Y” (but not both). If you do not quote specifically X and Y, make sure to write of+the+something or of+pronoun as in the first example. Notice that the verb is always singular.

“Was either of the drivers hurt in the accident?”
“Either Mathew OR John can do the job.”

• “Neither” means “NOT X and NOT (NOR) Y.” Although people often use “or” with “neither,” it is more grammatically correct to use “nor”. If you do not quote specifically X and Y, make sure to write of+the+something or of+pronoun as in the second example. Notice that the verb is always singular.

“Neither Frank nor John came to the party.” “Neither of the music stores has the CD.”

• “Both” means “X and Y”. Notice that the verb is always plural.

“I've got holes in both of my shoes!”
“Both the front tire and the back tire are flat.”

Exercises:

1. Exercise 1 (Both either and neither)
2. Exercise 2 (Both either and neither)
3. Exercise 3 (Both either and neither)
4. Exercise 4 (neither... nor, either or)
5. Exercise 5 (neither... nor, either or)

Modified from http://grammar.reverso.net/F_either_neither_both.shtml