If you always do something at a time, you can use the word ‘every’.

– examples:

I have a shower every morning.
I go to English class every Monday.
I read every night before going to sleep.

More than one

Using ‘every’ is easy: it does not matter if it is one day, two days, five weeks, or a hundred years.

I work every day.
I go to the cinema every 2 weeks.
I have a birthday every year.
I go home every Christmas.
I clean the dishes every 2 days.

(Note: the word ‘each’ can also be used; it has a slightly different meaning, however:
every = collective; all of them together
each = individually, but thought about at the same time)

Exercise

Answer these questions:

What do you do every day?
What do you do every 2 or 3 weeks?
What do you do every year?
What do you do every 4 or 5 years?