Grammar - indefinite article

study ex 1 ex 2 ex 3 ex 4
 
1. Sounds
The indefinite articles are A or AN.
We use A before a consonant-sound.
We use AN before a vowel-sound.
The difference depends on the sound of the vowels and consonants, not the spelling!
 
2. Examples
a teacher
a peach
a woman
a house
a man
a useful book
a university
a European
an English teacher
an orange
an old woman
an hour
an honest man
an heir
an honour
an Irish person
 
3. Use
A or AN is used before names of professions:
He is a painter.
My sister is studying to be a doctor.
It's really nice to be a student.
A is used before words like couple, dozen, hundred, thousand, million, ...:
A couple of years ago I was living in Britain.
There were a thousand people in the stadium.
A or AN means 'every' or 'each' in some expressions of time, speed, price,...:
She visits me twice a year.
He drives 50 miles an hour.
Don't put A or AN before uncountables:
I don't like milk.
Silence is golden.
We're having soup for lunch.