A, an and some

Start with the noun

A noun names a person, thing, place or idea. A countable noun can name separate items: one key, two keys. A singular noun names one; a plural noun names more than one.

An uncountable noun names something that English treats as an amount or a whole in that meaning: sand, furniture, advice. You do not count these directly as one sand, two sands when you mean the material. A learner's dictionary tells you how a noun is used. It may not work like the word in your language.

One of a kind or group

A and an are two forms of the indefinite article. An article is a small word before a noun or the words describing it. Use a/an when you introduce one person or thing without expecting the listener to identify which one already.

• We found a ring beside the bench.
• There is an insect on your sleeve.

You may know exactly which ring you found. The article does not mean that you know nothing about it. It means that you are not presenting it as the ring that your listener can already identify. Compare I found a ring. The ring has a green stone. The second sentence can use the because the ring has now been introduced.

You also use a/an to say what kind of person or thing someone or something is, including a job. The noun gives a type or group, not a unique identity.

• My aunt is a dentist.
• Omar is an artist.
• That building is a library.

Do not put another ordinary determiner directly after the article. A determiner is a word such as my, this or some that helps identify a noun or its quantity. Say my bicycle or a bicycle, not a my bicycle. See A, an or the?: introducing and identifying for identifying something with the.

A or an: the next sound

Use a before a consonant sound and an before a vowel sound. These are kinds of speech sound, not just the written letters. The letters a, e, i, o, u can represent different sounds. Listen to how the next word begins.

The same rule works with letters read aloud. An MP3 player begins with the sound of the letter name M, which starts like em. Choose from what you say, not from the shape of the first letter.

In ordinary unstressed speech, a is usually /ə/ and an is /ən/. The spelling still follows the sound rule. You do not need to add a stronger sound to make the article correct.

Adjectives and other words before the noun

An adjective describes a noun: quiet in a quiet room. Choose a/an by the sound immediately after the article, even when that word is not the noun.

• a quiet room; an empty room
• an unusual painting; a very unusual painting

In a very unusual painting, very comes next and starts with a consonant sound. Do not choose an from the later word unusual. Adding a description does not remove the article: She is a skilled driver.

With plural and uncountable nouns, a description does not make a/an possible: some fresh vegetables and some useful advice, not a fresh vegetables or an useful advice. The noun's use and the next sound are separate checks.

Some: a number or an amount

The basic quantity use of some gives a number or amount without saying exactly how much or how many. Use it with plural countable nouns or uncountable nouns. It is often unstressed, pronounced /səm/.

• I packed some sandwiches for the walk.
• We need some glue for this model.

The basic quantity use of some does not tell you an exact number. Stressed some can contrast with all, as you will see below. It is not a replacement for a/an before every noun. For one ordinary countable item, use a/an: I need a folder. For an unspecified number, use some folders.

Furniture and money refer to things you can see or handle, but English treats these words as uncountable in these meanings. Countability is a property of the word and its use, not a test of whether you can touch the thing.

Some, any and a/an in questions and negatives

You can keep a/an in a question or a negative with a singular countable noun: Do you need a towel? I haven't got a towel. You do not change a into some just because the sentence becomes a question.

With plurals and uncountable nouns, use some in positive sentences and usually any in open questions or negatives about a zero quantity. A positive sentence says that something is so; a negative uses a word such as not to say it is not so.

Use some in offers and requests, and when you expect a yes answer. These are questions too, so do not learn the false rule that every question needs any.

• Would you like some soup?
• Could you bring some plates, please?

Any is also possible in questions with different expectations. The full choice is in Some and any: someone, anything, somewhere and related forms. The basic negative pattern means none at all; later uses of stressed some do not follow a simple positive-versus-negative rule.

When you do not need some

Some is possible, not compulsory, before a plural or uncountable noun. You can leave the noun without a determiner. For a statement about a whole kind of thing, use the plural or uncountable noun without some.

• Bicycles need regular care. Bicycles in general.
• Sand can get into your shoes. Sand as a material.

Compare Some bicycles are parked outside. This is a number of bicycles in a situation, not a statement about all bicycles. You can also say There are bicycles outside without giving a number. A bare noun does not always mean things in general.

We bought bread and We bought some bread are both possible. Do not insert a just because the sentence has no determiner. See No article (zero article) for the wider patterns without an article.

Portions and changes of meaning

To count an uncountable amount, name a unit, container or separate item: a bag of flour, a piece of advice, two bottles of oil. The article belongs to the countable word bag, piece or bottle, not directly to the uncountable noun.

A noun can also change its countability when its meaning changes. This is an extension beyond the basic table, not permission to put a/an before any uncountable noun.

Check the intended meaning before calling a form wrong. A coffee can mean a cup or serving. That does not mean an advice works in the same way. See Countable and uncountable nouns: a bag, some luggage for more meaning changes and counting expressions.

Later uses of some

Some without a noun: when the noun is understood, you can leave it out: We need more envelopes. Have you got some? Here some refers back to envelopes. It is a pronoun, a word standing for a noun or noun phrase.

Some of: use some of before a known group marked by the, these or a possessive such as my: Some of my neighbours cycle to work. Compare some neighbours with some of my neighbours. Do not combine them as some my neighbours. See Some and any: someone, anything, somewhere and related forms for pronouns and part-of-group patterns.

Stressed some: pronounced /sʌm/, it can contrast one part with another: I don't like some of these designs means that particular designs are not to your taste. It does not say you dislike every design. A negative sentence can therefore contain some.

Stressed some can also go with a singular countable noun for a particular but unidentified person or thing: Some visitor left this scarf here. This is not the unstressed amount pattern some bread. Do not turn the beginner quantity rule into a ban on every singular use. Other strong uses, including some with a number, are covered in Some and any: someone, anything, somewhere and related forms.

What comes next

Use A, an or the?: introducing and identifying for new versus identifiable reference, A, an or one: counting and describing for the article versus the number one, Countable and uncountable nouns: a bag, some luggage for noun meanings and units, Some and any: someone, anything, somewhere and related forms for quantity questions and stronger some/any meanings, No article (zero article) for nouns without an article, and Much, many and a lot of: few, a few, little and a little for other quantity words.