Expressions of Frequency

 

If we want to specify how often something is done we can use an expression of frequency, for example every week, twice a day, once in a while, from time to time, every so often, every other day.
We generally place expressions of frequency at the end of the sentence.

Examples:

I play football three times a week.
He cooks dinner five times a month.
They see each other once in a while.

We say a week, a day, an hour etc. We can also say per but it is more formal:

Examples:

This job pays $50,000 per year.
This car can go at 150 miles per hour.

We don't usually say one time, we say once. We don't usually say two times, we say twice. More than twice we say times: three times, ten times, one hundred times etc.

Examples:

She cleans the house once a week.
They go on holiday twice a year.
I go to the gym three times a week.