We always use the-sform for third person singular present simple:
Good healthdependson having a good diet.
Not:Good health depend on having a good diet.
The buildinghasthree rooms.
Not:The building have three rooms.
We don’t use the present simple for actions that are going on at the present time. We use the present continuous:
Look, she’swinning!
Not:Look, she wins!
We use the present simple, notwill, for future reference after words likewhen,before,as soon as,ifandwhether:
We’ll come and pick you up as soon as youcall.
Not:We’ll come and pick you up as soon as you’ll call.
We don’t use the present continuous for facts and permanent situations. We use the present simple:
Six plus fourmakesten.(6 + 4 = 10)
Not:Six plus four is making ten.
We don’t use the present continuous with some verbs, e.g. verbs expressing feelings, describing senses, mental process verbs:
Horrible weather, isn’t it? But Ihearit’s going to get better at the weekend.
Not:I’m hearing it’s going to get better.
Some childrenhateplaying any sport.
Not:Some children are hating…
We don’t use the present simple or the present continuous beforesincewhen we talk about a specific time up to now. We use the present perfect:
I’vebeenhere since 4 o’clock.
Not:I’m here since 4 o’clock.
See also:
Present