We use Infinitives without the word to when they come after modals:
There are three uses of the word to before the Infinitive:
You should
Infinitives have two forms:
it is forbidden
Can, could, may, might, shall, would, should, and must.
1. To indicate an intention 2. After specific main verbs like agree, forbid, fail, begin, choose, decide, prepare, try, want, etc. 3. After specific adjectives
with to before the verb, and without to.
to play in the park right now.
study to get a 10 at the exam.