-'s

I UK / US short form

1) a way of saying or writing "is" and "has". This is not often used in formal writing

She's in the kitchen.

John's gone out.

2) spoken a way of saying "does" in some questions, that many people consider to be incorrect

How's that look?

3) the usual way of saying or writing "us" when you use it with "let" to make a suggestion

Let's not tell him now – let's give him a surprise.

II UK / US suffix

1)

a) used with nouns for showing who or what something belongs to

I've never met Andy's wife.

The dog's leg was badly cut.

b) used with nouns to show a connection or relationship

Phil's work (= the work he does)

the evening's activities (= activities that happen in the evening)

2) used for talking about the home of a particular person

We all went back to Alan's for lunch.

3) used for talking about some types of shops

He gets most of their meat at the butcher's.