A + consonant sound (/b/, Idl, Ig/, If/, 11/, Ip/, etc.) a pen
an + vowel sound (/re/, lei, III, 10/, /al, etc.) an apple
1. A /An is used with singular countable nouns when we talk about things in general.
An aeroplane is faster than a train. A greengrocer sells vegetables.
(Which aeroplane? Aeroplanes in general.) (Which greengrocer? Greengrocers in general.)
2. We often use a /an after the verbs 'to be' and 'have I have got'.
He is a photographer. He has got a camera.
3. A /An is not used before an adjective if it is not followed by a noun. However, if the
adjective is followed by a noun, we use a if the adjective begins with a consonant
noun and an if the adjective begins with a vowel sound.
It's a ring. It's expensive. It's an expensive ring.
4. We do not use a /an with uncountable or plural nouns. We can use some instead.
Would you like some tea? Yes, please! And I'd like some biscuits.
(NOT Would you like a-tea?)
5. We use either a /an or the before a singular countable noun to represent a class
of people, animals or things.
A I The dolphin is more intelligent than a I the shark. (We mean dolphins and sharks in
general.)
ALSO: Dolphins are more intelligent than sharks.
Пояснение: сорри брат