Old is most commonly used for describing the age of a person or thing. For example, you say that someone ‘is forty years old’.
Legally, witnesses must be at least fourteen years old.
They found bits of bone which are three-and-a-half million years old.
You can also describe someone as, for example, ‘a forty-year-old man’. Don't say ‘a forty-years-old man’.
She married a sixty-year-old man.
Sue lives with her five-year-old son John in the West Country.
You can also say that someone is ‘a man of forty’. However, don't say ‘a man of forty years old’.
Maya is a tall, strong woman of thirty.
Actually, he looks good for a man of 62.
asking about age
You use old after how when you are asking about the age of a person or thing.
‘How old are you?’ – ‘I’ll be eight next year.'
‘How old is the Taj Mahal?’ – ‘It was built in about 1640, I think.’
another meaning of ‘old’
You can also use old to describe someone who has lived a very long time.
She was a very old lady.
He was very thin and he looked really old.
This use of old can sometimes sound rude. Elderly is a more polite word.
I look after my elderly mother.
Like many elderly people, Mrs Carstairs could remember voices better than faces.
You can talk about old people as the elderly.
This is one of the many organizations which help the elderly.
An old friend is someone who has been your friend for a long time. He or she is not necessarily an old person.
Some of us took the opportunity to visit old friends.
‘old’ used for describing objects
An old building or other object was built or made a long time ago.
The museum is a massive old building.
The drawers were full of old clothes.
Old can sometimes mean ‘former’. For example, your ‘old teacher’ is someone that used to be your teacher. He or she is not necessarily an old person.
Jane returned to her old boyfriend.
I still like to visit my old school.