a

ONE

A1used before a singular noun when you are talking about one person or thing that has not been mentioned before

• I've got a new phone.
• There's a cat in the garden.

ANY

A1used to talk about any example of a type of person or thing

• A dog needs regular exercise.
• Do you have a pen I could borrow?

JOB

A1used before a noun that says what job someone does or what kind of person they are

• My sister is a nurse.
• He's a really good cook.

EACH

A2used to mean 'each' or 'every' when talking about prices, speeds and how often

• I go swimming twice a week.
• The apples are two pounds a kilo.