BEFORE NOUN›used before a noun to refer to a single thing or person but not a particular thing or person or not one that you have referred to before: I need a new car.I bought a nice coat yesterday.I saw a woman speaking to him.
ONE›one: a hundred dollarsa dozen eggs
EVERY/EACH›every or each: A child needs love.Take one tablet three times a (= each) day.
TYPE›used to say what type of thing or person something or someone is: It's a guinea pig.She's a doctor.
AN ACTION›used before some action nouns when referring to one example of the action: I'm just going to have a wash.Take a look at this.
TWO NOUNS›used before the first of two nouns that are often used together: a cup and saucer
AMOUNTS›used before some phrases saying how much of something there is: a few daysa bit of sugar
NAME›used before a person's name when referring to someone you do not know: There's a Ms Leeming to see you.