Which word goes in front of the noun, and when nothing does
I bought a book - I bought the book - I bought books
How to use this sheet
English offers three articles-worth of choice in front of a noun, not two, because using nothing at all is itself a grammatical option with its own meaning. The indefinite article introduces one item the listener has not met before and is singular only. The definite article claims the listener can work out which one you mean, and works with singular, plural and uncountable nouns alike. No article at all makes a general statement, and is available only to plural and uncountable nouns. A singular countable noun therefore always needs one of the two articles or another determiner: it is the one case where leaving the slot empty is never correct.
| Noun | What you mean | In front | Example |
|---|---|---|---|
| Singular countable | One, new to the listener | indefinite article | She has a meeting at four. |
| Singular countable | One, identifiable | definite article | The meeting was cancelled. |
| Singular countable | Never nothing | always one or the other | She has meeting at four. |
| Plural countable | In general | nothing | Meetings waste a lot of time. |
| Plural countable | Particular ones | definite article | The meetings on Friday were useful. |
| Uncountable | In general | nothing | Water freezes at zero degrees. |
| Uncountable | A particular quantity | definite article | The water in this jug is warm. |
| Uncountable | Never the indefinite one | impossible | She gave me an advice. |
| Any noun | Second mention | definite article | I saw a dog. The dog was limping. |
| Any noun | Made unique by what follows | definite article | The report you sent has arrived. |
| Superlative | Only one possible | definite article | She is the tallest in the office. |
| Meals, institutions | The activity, not the building | nothing | We had breakfast before school. |
In use
I need a chair for the meeting, and the chair in the corner will do. Cats sleep for most of the day, but the cats next door never seem to. She studies medicine at university in a city I have never visited.
Watch out
She gave me an advice about the interview, so I bought new suit.
Two opposite errors sit in that one sentence. The first noun cannot take the indefinite article at all, because it is uncountable in English even though the matching word in many other languages is countable; you either drop the article or add a counting word in front. The second noun is singular and countable, and its slot has been left empty, which English never allows: it needs an article or a possessive. Learners whose first language has no articles produce the second error constantly and rarely notice it, because nothing about the sentence sounds broken to them. Check every singular countable noun you write; that single pass catches more than any rule.