Many Czech learners mistakenly add to after modal verbs like must. But in English, this doesn’t work!
The rule:
❗ must + base form of the verb – no to
✔️ I must go, you must study, we must leave.
The same rule applies to other modal verbs like can, should, could, might, may – no to after them either!
W: I must to go to the bank tomorrow.
R: I must go to the bank tomorrow.