RULE: We use or + a singular countable noun when the listener/reader doesn't know exactly which thing we are talking about. You can have an apple or a banana We have a new car. noun when it is clear which things) or person/people we are talking about. The apples in this pie are from our yard The bananas that I bought yesterday are horrible +plural countable noun or uncountable noun, when we are talking about things in general Bananas are sweeter than apples. Chocolate isn't good for you.​