used to join two words or sentence elements to indicate that what immediately follows is another alternative
used to join two sentence elements of the same class or function and often introduced by either to indicate that what immediately follows is another or a final alternative
either sink or swim
whether you like it or not
used before the second and later of several suggestions to indicate approximation or uncertainty
five or six days
used after a negative and not
She never drinks or smokes
used to introduce an alternative word or phrase mentioned by way of definition or explanation of a preceding word or phrase another word
a heifer or young cow
used to indicate the result of rejecting a preceding choice
Hurry or you'll be late
used to introduce an afterthought
Shall I tell you more – or am I boring you?