Undefined Articles
by cindy romero
1. Use a to refer to an example of something.
1.1. Examples
1.1.1. The mouse had a tiny nose . The elephant had a long trunk
2. Use a with singular nouns after the words 'what' and 'such'
2.1. Examples
2.1.1. What a shame ! She's such a beautiful girl
3. Use a meaning 'one', referring to a single object or person, or a single unit of measure. In these sentences using "one" instead of the indefinite article is grammatically correct. It will add emphasis to the number, and contrast with other numbers.
3.1. Examples
3.1.1. I need a kilogram of sugar. I need one kilogram of sugar. You can't run a mile in 5 minutes
4. The indefinite article is used to refer to something for the first time or to refer to a particular member of a group or class. Some use cases and examples are given below. Use a to refer to something for the first time.
4.1. Examples
4.1.1. Would you like a drink? I've finally got a good job
5. Naming members of a group Use a with names of jobs.
5.1. Examples
5.1.1. John is a doctor. Mary is training to be an engineer.
6. Use a with nationalities and religions in the singular.
6.1. Example
6.1.1. John is an Englishman.
7. Use a with the names of days of the week when not referring to any particular day
7.1. Example
7.1.1. I was born on a Thursday.