This is the 74th most frequent Czech word.
musí
"Musí" means "must" or "has to."
The word "musí" is used here to indicate a customary or social obligation for someone else.
Dítě musí poslouchat rodiče.
The child must obey the parents.
The word "musí" is used here to infer a logical conclusion.
Musí být nemocný, když dnes nepřišel.
He must be sick if he didn't come today.
The word "musí" is used here to indicate a personal necessity or obligation.