Either and Neither

The English words either and neither can cause some problems for native and non-native speakers of English. Sometimes you can use either one and sometimes you have to choose either one or the other, but neither one is very difficult.

Either... Or

Either... or is used to offer a choice between two possibilities:

Either Mike or Lisa will be there.
Either you leave me alone or I will call the police.
We should bring either coffee or tea.
You can either help us or go to your room.

Either can also be followed by (one) of + group of two:

Either of us could do it
Either one of us could do it
Either of you should know
Either one of you should know

Not... either... or denies both possibilities:

I don't think either Mike or Lisa will be there.
He doesn't speak either English or French.

Not... either is used after a negative statement.

I don't speak French.
You don't either.
He isn't ready to go.
We aren't either.

Neither... nor

Neither... nor is equivalent to not... either... or.

Neither Mike nor Lisa will be there.
He speaks neither English nor French.
We brought neither coffee nor tea.
I will neither help you nor go to my room.

Neither can also be followed by (one) of + group of two:

Neither of them is ready.
Neither one of them is ready.
Neither of us has any money.
Neither one of us has any money.

Neither is used like not... either.

I don't speak French.
Neither do I.
(informal): Me neither.
He isn't ready to go.
Neither are we.

The Bottom Line

Either means one, neither means none, and not either equals neither. Or goes with either and norgoes with neither.
  

From: e Learn English Language - Online language learning with Laura K. Lawless