ought to
Have/Has
Doesn't have to
Don't/Doesn't have to
Have to
Has to
Must to
When we have the negative form of "have to " (don't/ doesn't)
Ought to
Don't have to
We ----- be quiet in the library
I ----- make this proyect
We use it to say that is necessary to do something
You ------ wake up early on the weekend
The part of "have to ", doesn't change, it stays normal
It has a authority level higher than have to
A teacher ------ make all its planifications at time
It's used to replace have to, but in a formal way
My mom ------- help me with my work
We use it to say that is not necessary to do something but we can do it if we want