Questions & Answers about Ты должен повторять слова каждый день.
Why does the sentence use должен instead of надо or нужно?
All three express obligation or necessity, but they are used slightly differently.
Должен is personal and stronger, closer to must / have to.
Structure: [person] + должен + infinitive
Example: Ты должен повторять слова каждый день.
This sounds like a clear rule or duty directed at you.Надо / нужно are impersonal and often sound a bit softer, closer to need to / should.
Structure: (кому?) + надо / нужно + infinitive
Example:- Тебе нужно повторять слова каждый день.
- Надо повторять слова каждый день. (general advice, no specific person)
So the choice of должен emphasizes that the obligation is clearly attached to ты and may sound a bit stricter or more categorical than нужно or надо.
What does должен agree with, and how would the sentence change for a woman or for several people?