you had to use telescopes.

you has to use telescopes.

you have to use telescopes.

you are having to use telescopes.

you must go to the hospital.

you had to go to the hospital.

you would go to the hospital.

you could go to the hospital.

you can see the birds clearly.

you could see the birds clearly.

you would see the birds clearly.

you might see the birds clearly.

you got angry.

you have gotten angry.

you get angry.

you are getting angry.

teachers were always happy.

teachers are always happy.

teachers will always be happy.

teachers would be always happy.

I walk to school.

I walked to school.

I am walking to school.

I was walking to school.