BETWEEN POSSIBILITIES›used between possibilities, or before the last in a list of possibilities: Would you like toast or cereal?Is that a boy or a girl?You can have beer, wine, or mineral water.The house will take two or three years to complete.
CHANGE›used to change or correct something you have said: We told the truth, or most of it.
REASON›used to give a reason for something you have said: She must love him or she wouldn't have stayed with him all these years.
NOT EITHER›used after a negative verb between a list of things to mean not any of those things or people: Tim doesn't eat meat or fish.She doesn't have a telephone or a fax machine.