Learn Hardcore Russian: Ты должен прочитать это предложение.

должен is a short-form adjective used as a modal expression meaning “must” or “have to.” It expresses obligation and is always followed by an infinitive (here, прочитать).

Why is прочитать used instead of читать?

прочитать is the perfective aspect of “to read,” indicating that the action will be completed (reading the entire sentence). читать is imperfective and would only convey an ongoing or habitual reading, not a one-time completed action.

What case is это предложение in, and why?

It’s in the accusative case because прочитать takes a direct object. For neuter inanimate nouns like предложение, the accusative form is identical to the nominative: это предложение.

Why does должен not change to должна here?

Short-form adjectives agree in gender with the subject. If the speaker or the person being addressed is male, it’s ты должен. A female speaker addressing you or a female “you” would say ты должна прочитать….

Can you drop ты and still be understood?

No, in this case you need ты, because должен does not have a unique ending for person (unlike verbs). Without ты, the sentence would lack a clear subject.

How do you pronounce должен?

It’s pronounced [daʎˈʐen], roughly dahl‑ZHEN, with the stress on the second syllable and the “ж” like the “s” in “vision.”

Could you use тебе нужно instead of ты должен?

Yes. You can say тебе нужно прочитать это предложение. нужно is an impersonal modal word that takes a dative object (here, тебе) plus an infinitive to express necessity.

Is the word order flexible in this sentence?

Yes. Russian allows you to say Ты должен это предложение прочитать or Это предложение ты должен прочитать, shifting emphasis. The core meaning stays the same.

What’s the difference between the short form должен and the full form должный?

The short form должен is used as a modal predicate to express obligation and stands alone with an infinitive. The full form должный is a regular adjective meaning “due” or “proper,” declines by gender, number, and case, and doesn’t carry a modal “must” sense.