used before countable or singular nouns referring to people or things that have not already been mentioned
a man/horse/unit
an aunt/egg/hour/X-ray
I can only carry two at a time.
There's a visitor for you.
She's a friend of my father's (= one of my father's friends).
used to show that somebody/something is a member of a group or profession
Their new car's a BMW.
She's a Buddhist.
He's a teacher.
Is that a Monet (= a painting by Monet)?
any; every
A lion is a dangerous animal.
used before uncountable nouns when these have an adjective in front of them, or phrase following them
a good knowledge of French
a sadness that won’t go away
used in front of two nouns that are seen as a single unit
a knife and fork
used instead of one before some numbers
A thousand people were there.
used when talking about prices, quantities and rates
They cost 50p a kilo.
I can type 50 words a minute.
He was driving at 50 miles an hour.
a person like somebody
She's a little Greta Thunberg.
used before somebody’s name to show that the speaker does not know the person
There's a Mrs Green to see you.
used before the names of days of the week to talk about one particular day
She died on a Tuesday.
the first letter of the English alphabet
‘Apple’ begins with (an) A/‘A’.
the 6th note in the scale of C major
a grade that a student can get for a piece of work or course of study that shows that it is excellent
She got (an) A in biology.
He had straight A's (= nothing but A's) all through high school.
used to represent the first of two or more possibilities
Shall we go for plan A or plan B?
used to represent a person, for example in an imagined situation or to hide their identity
Assume A knows B is guilty.
from one place to another
For me a car is just a means of getting from A to B.
including everything there is to know about something
He knew his subject from A to Z.
used in the UK before a number to refer to a particular important road
the A34 to Newbury
used (but not in the US) before numbers that show standard metric sizes of paper
a sheet of A4 paper (= 297×210mm)
A3 (= 420×297mm)
A5 (= 210×148mm)
(in writing) amp
not; without
atheist
atypical
asexually
a very successful US musical play (1975) and film (1985) about dancers trying to get a part in a Broadway show. The play won a Pulitzer Prize and a Tony Award. The music was written by Marvin Hamlisch and the words by Edward Kleban. The show ran for 6 137 performances on Broadway between 1975 and 1990, at that time more than any other show in history. A film with the same name was made in 1985.
a short novel (1843) by Charles Dickens. It is about Ebenezer Scrooge, a mean old man, who on the night before Christmas sees ghosts of Christmasses past, present and future. He realizes that he has been very unpleasant to people and that no one likes him. He immediately changes and sends gifts to his poor employee, Bob Cratchit, and to Cratchit's family, including his little lame son, Tiny Tim.
a novel (1962) by Anthony Burgess which was made into a film by Stanley Kubrick in 1971. The story is set in the future and is about a young man, Alex, who loves violence and the music of Beethoven. The characters all speak a future version of English invented by the author.
used before plural nouns to mean ‘a small number of’ or ‘a few’
It's only a couple blocks away.
a sequence of twelve novels by the English author Anthony Powell (1905-2000), published between 1951 and 1975. The novels present a broad picture of the British upper and middle classes during those years and are known for their very large range of characters, including the very ambitious Kenneth Widmerpool. A television version of the series was broadcast in 1997.
