| either = one OR the other | Would you like tea or coffee? ∼ Either; I don’t mind. (= ‘You can give me tea OR coffee; I have no preference.’) |
| neither = not one and not the other | Would you like ham or beef in your sandwich? ∼ Neither; I’m a vegetarian. (= ‘I don’t want ham and I don’t want beef.’) |
| both = the first AND the second | I take both milk and sugar in my coffee. (= ‘I take sugar. I also take milk.’) |
| We use either with a singular noun. We use either of with a plural noun. We use a singular verb with either and either of. | either car either of the cars Either day is fine for me. Either of the days is fine for me. |
| We use neither with a singular noun. We use neither of with a plural noun. We use a singular verb with neither and neither of. | neither house neither of the houses Neither day was suitable. Neither of the days was suitable. |
| We use both with a plural noun. | both houses both of the houses Both (of) my brothers are tall. |
| We use of before the pronouns us, you, them. | both of us, both of you, either of them, neither of them, etc. |
| Between of and a noun we use these, those or my, your, John’s, etc., or the. | both of those houses, neither of my brothers, both of John’s sisters, either of the cinemas |