(よん)

よん
number
four
1. four
The number four. This reading (よん) is more commonly used in modern Japanese than し because し sounds like () (death). よん is generally preferred when counting and in most compound numbers.
We had a meal with four people.
There are four apples.
Using よっつ counter
It's forty-five minutes.
My family has four people: my father, mother, older sister, and me.

Japanese has two readings for four: よん and し. よん is more common because し is homophonous with () (death), making it inauspicious. However, し is used in some set expressions like ()(がつ) (shigatsu, April) and ()() (yoji, four o'clock—note this is an exception using よ). When counting with つ, it becomes (よっ)つ (yottsu).