either ... or
used in positive statements
You use either and or when you are mentioning two alternatives and you want to show that no other alternatives are possible. You put either in front of the first alternative and or in front of the second one.
Recruits are interviewed by either Mrs Darby or Mr Beaufort.
He must have thought that I was either stupid or rude.
I was expecting you either today or tomorrow.
People either leave or are promoted.
Either she goes or I go.
used in negative statements
You use either and or in negative statements when you are emphasizing that a statement refers to both of two things or qualities. For example, instead of saying ‘I haven’t been to Paris or Rome', you can say ‘I haven’t been to either Paris or Rome'.
He was not the choice of either Dexter or the team manager.
Dr Li, you're not being either truthful or fair.
➜ See neither ... nor