Radim can mean “I work” or “I’m working”: Serbian and Montenegrin do not add a form of “to be” to make that present-tense action sentence. But “I’m well” is Ja sam dobro. The sam belongs there. Learn the verb patterns and this distinction together.
Published 7 June 2026 · Updated 10 September 2026
Start with common action verbs and biti (to be). Both help you speak immediately. A verb such as raditi has a present stem and personal endings; its present form can cover English simple and continuous meanings. That does not make biti unnecessary in sentences about who someone is or how they are. Our beginner’s roadmap puts these building blocks in context.
Take raditi (to work). Drop -iti, keep the stem rad-, add:
| Person | Ending | Raditi |
|---|---|---|
| ja (I) | -im | radim |
| ti (you, sing.) | -iš | radiš |
| on/ona/ono | -i | radi |
| mi (we) | -imo | radimo |
| vi (you, pl./formal) | -ite | radite |
| oni/one (they) | -e | rade |
These are the six forms of raditi, not a complete recipe for every verb. Other classes have different vowels and third-person plural endings; some verbs also change their stem. Learn the first-person singular and third-person plural when you meet a new verb.
Here are three useful examples. The kupujem pattern is part of the broader -em/-jem group, not the only pattern in that group:
| Person | -a- family pričati (talk) | -i- family govoriti (speak) | -uje- family kupovati (buy) |
|---|---|---|---|
| ja | pričam | govorim | kupujem |
| ti | pričaš | govoriš | kupuješ |
| on/ona | priča | govori | kupuje |
| mi | pričamo | govorimo | kupujemo |
| vi | pričate | govorite | kupujete |
| oni/one | pričaju | govore | kupuju |
Compare the first-person singular and third-person plural: pričam/pričaju, govorim/govore, kupujem/kupuju. Many verbs in -ovati follow the kupovati → kupujem pattern, including putovati → putujem. Check new verbs individually: the infinitive does not always reveal the present stem.
A small handful of everyday verbs skip the families entirely, the same way English speakers memorise "go, went, gone" without asking why:
These four are a useful starting set, not the whole inventory of irregular verbs. Notice that ići has the present stem id-, while moći alternates between mog- and mož-.
Use the short present forms of biti: sam, si, je, smo, ste, su. They connect the subject to a description or identity: Ja sam dobro (I’m well), Ona je studentkinja (She is a student), Mi smo spremni (We are ready, for a mixed or masculine group).
Compare Radim danas (I’m working today) with Danas sam dobro (I’m well today). The first has the action verb radim; the second needs sam. Omitting a subject pronoun does not mean omitting the verb “to be”.
You can often omit ja, ti or mi when the speaker is clear. Include a pronoun for contrast, emphasis or clarity: Ja radim, a on ne radi (I work, but he doesn’t). Endings do not always identify a unique person: mogu can mean “I can” or “they can”, so context matters.
Do Serbian and Montenegrin need a separate word for “is” or “are”? Yes, in ordinary sentences such as Ona je dobro (She is well), the form je is needed. An action verb such as radim can mean I work or I am working without adding sam. These are different sentence patterns.
Do you always need the pronoun before the verb? No. You can often omit it when the subject is clear, and include it for emphasis, contrast or clarity. Context still matters because some forms, such as mogu, are shared by more than one person.
Are the six forms of raditi enough for every verb? No. They show one useful pattern. Learn other classes, their third-person plural forms and important stem changes. Start with a small set of common verbs rather than assuming one set of endings works everywhere.
Why does kupovati become kupujem? Many verbs in -ovati form the present with -ujem, as in kupujem and putujem. Learn this pattern, but check the present forms of unfamiliar verbs rather than applying it to every infinitive.
The present tense is the ammunition you need before the real grammar boss fight: verbal aspect, where nearly every verb has a twin depending on whether the action is ongoing or finished. Once the present is automatic, the past tense (perfekt) is a short hop — it leans on the very biti forms you just met. When a verb takes a direct object, the accusative case is useful. If you want the whole sequence in order, our beginner's roadmap for Serbian lays it out.
Practise a small set of verbs in sentences, then add new patterns. You can start learning with Gora and use these examples for your next speaking practice. See the supporting present-tense explanation and irregular verb tables by linguist Larisa Zlatić.