a

determiner (NOT PARTICULAR)

weak /ə/ strong /eɪ/ (also an)

Definition

A1 used before a noun to refer to a single thing or person that has not been mentioned before, especially when you are not referring to a particular thing or person: I've bought a car. She's got a boyfriend. There was a sudden loud noise. What a shame that you couldn't go to the party. I heard a child crying. Is he a friend of yours (= one of your friends)? A1 used to say what type of thing or person something or someone is: She wants to be a doctor when she grows up. This is a very mild cheese. Experts think the painting may be a Picasso (= by Picasso). A1 used to mean any or every thing or person of the type you are referring to: Can you ride a bike? A cheetah can run faster than a lion. A teacher needs to have a lot of patience. › used before some uncountable nouns when you want to limit their meaning in some way, such as when describing them more completely or referring to one example of them: I only have a limited knowledge of Spanish. He has a great love of music. There was a fierceness in her voice. A2 used before some nouns of action when referring to one example of the action: Take a look at this, Jez. I'm just going to have a wash. There was a knocking at the door. A2 used when referring to a unit or container of something, especially something you eat or drink: I'd love a coffee. All I had for lunch was a yogurt. A2 used before the first but not the second of two nouns that are referred to as one unit: a cup and saucer a knife and fork A2 used before some words that express a number or amount: a few days a bit of wool a lot of money › used in front of a person's name when referring to someone who you do not know: There's a Ms Evans to see you. › used in front of a person's family name when they are a member of that family: Is that a Wilson over there? › used before the name of a day or month to refer to one example of it: My birthday is on a Friday this year. It's been a very wet June.

(Definition of a determiner (NOT PARTICULAR) from the Cambridge Advanced Learner's Dictionary & Thesaurus © Cambridge University Press)