Aspect after phase and modal verbs
In short
| Verb | Complement | Example |
|---|---|---|
| početi | da + imperfective only | počeo sam da učim |
| nastaviti | da + imperfective only | nastavila je da studira |
| prestati | da + imperfective only | prestao je da kasni |
| modal, one task | da + perfective | moram da uradim domaći do sutra |
| modal, habit | da + imperfective | moram da radim domaći svaki dan |
Phase verbs: never a perfective after them.
B1 · Lesson 23 · Vid uz fazne i modalne glagole
The full explanation, from the lesson that teaches this rule
You already know that most Serbian verbs come in pairs: an imperfective one for an action seen as ongoing or repeated (učiti, pisati, čitati), and a perfective one for an action seen as one finished whole (naučiti, napisati, pročitati). Until now you chose between them yourself. In this lesson some verbs make that choice for you.
Start, continue, stop: always the imperfective
Three verbs talk about the phases of an activity: when it begins, whether it goes on, and when it ends. Think about what they describe: you can only start, continue or stop something that lasts. A finished whole has no middle to continue and no point where you can stop halfway. So the verb that follows them is always imperfective. There is no choice here, and a perfective after them is simply wrong.
| Phase verb | Meaning | Example (da + imperfective) | Never |
|---|---|---|---|
| početi (počnem, počeo) | to start, begin | Počeo sam da učim srpski. | da naučim |
| nastaviti (nastavim, nastavio) | to continue, go on | Nastavila je da studira. | — |
| prestati (prestanem, prestao) | to stop, quit | Prestao je da izostaje s predavanja. | da izostane |
As with modal verbs, the second verb can be an infinitive (počeo sam učiti) or da + present (počeo sam da učim). Both are correct; this course uses the da-clause, the everyday Serbian choice. In the da-clause the second verb agrees with the subject: počeli smo da pišemo, prestala je da kasni.
The trap: the English start to learn or stop doing gives no hint, so learners reach for the verb they know best. Check the verb after početi, nastaviti and prestati: if it is a perfective like naučiti, napisati, pročitati, uraditi, swap it for its imperfective partner — učiti, pisati, čitati, raditi.
After modal verbs: the choice carries meaning
After morati, moći, hteti, trebati both aspects are possible, and the choice says something. A perfective means one concrete job that will be done and finished: this essay, this exam, today's homework. An imperfective means an activity in general, something you do regularly or keep doing.
| After a modal | What it means | Example |
|---|---|---|
| perfective | one task, done once and completed | Moram da uradim domaći do sutra. |
| imperfective | a habit, a regular or ongoing duty | Moram da radim domaći svaki dan. |
| perfective | one task, done once and completed | Mogu da napišem esej do petka. |
| imperfective | a habit, a regular or ongoing duty | Mogu da pišem samo uveče. |
Words around the verb usually tell you which you need: svaki dan, uvek, redovno, često, uveče point to the imperfective; do sutra, do petka, danas, ovaj esej, jedan ispit point to the perfective.
Ask yourself: is it one job with an end (perfective), or a way of life (imperfective)? Treba da položim ispit — pass this one exam. Treba da učim redovno — study as a habit.
Check what you read
3 of the 14 questions this lesson asks in the app. Type the form or pick the answer.
Počeo sam da ___ za ispit iz hemije. Which verb fills the gap?
Why is *Počeo sam da naučim srpski* wrong?
Počeli smo da ___ seminarski rad. Which verb fills the gap?
Examples from the course
The marked word is where the rule applies. Press play to hear the sentence.
Nastavila je da studira.
She continued studying.
Počeo sam da učim srpski.
I started learning Serbian. (man speaking)
Prestanite da pričate, pišemo test!
Stop talking (all of you), we're writing a test!
Prestao je da izostaje s predavanja.
He stopped skipping lectures.
Zašto si prestao da ideš na predavanja?
Why did you stop going to lectures? (to a man)
Kada ćeš početi da spremaš kolokvijum iz hemije?
When will you start preparing for the chemistry midterm?
Profesorka je počela da predaje tačno u devet.
The professor (a woman) started teaching at exactly nine.
Posle raspusta nastavićemo da učimo književnost i biologiju.
After the school holidays we will continue learning literature and biology.
Kad je dobila stipendiju, prestala je da plaća školarinu.
When she got a scholarship, she stopped paying tuition.
Nastavite da čitate, ja se vraćam za pet minuta.
Keep reading (all of you), I'll be back in five minutes.
Sentences in the course that use this rule: 21
Try it yourself
Translate a sentence that uses this rule. The check marks the word that went wrong and names the rule behind it, as in the app.
Sentences
Write it in Serbian
She continued studying.