Purpose clauses

When you say why you do something in the sense of what you want to achieve — "I'm learning German to find a better job" — English uses to, in order to or so that. Serbian has three tools for this: a da-clause with the present tense, the more formal kako bi with the conditional, and a short noun phrase with radi or zbog. A clause like this is called a purpose clause.

1. da + present: the everyday way

Put da and then the verb in the present tense, agreeing with whoever does it: Učim nemački da nađem bolji posao. (I'm learning German to find a better job.)

The key rule: the verb after da stays in the present, even when the main clause is in the past or the future. The goal is always seen from the moment of acting, so it is never put in the past: Juče sam otišao kod šefa da tražim povišicu. (Yesterday I went to the boss to ask for a raise.) — never da sam tražio.

The trap: after a past main verb, do not put the da-verb in the past. Otišli smo u London da radimo, not da smo radili. Past main clause, present da-clause.

2. When someone else is meant to do it

If the goal is for a different person to do something — "I sent her the report so that she could read it" — Serbian must use a da-clause, with the verb agreeing with that other person. An infinitive is impossible here, because an infinitive has no way to show who does it: Poslala sam izveštaj koleginici da ga pročita. (I sent the report to my colleague so that she could read it.)

3. kako bi + conditional: the careful, written way

In formal speech, reports, letters and careful writing, purpose is often expressed with kako plus the conditional you already know (bih, bi, bismo, biste + the l-participle). It means exactly the same as the da-clause, but sounds more official. The form of bi follows the person who does the action in the purpose clause:

The participle agrees in gender and number like in the past tense: kako bih otvorio (a man), kako bih otvorila (a woman). A kako bi clause may also open the sentence, followed by a comma.

4. Negative purpose: so as not to

To say what you want to avoid, put ne right before the verb: da ne + present, or kako ne bi + participle (ne goes before bi). Krenuo sam ranije da ne zakasnim. (I set off earlier so as not to be late.) Proveravamo ugovore kako ne bismo pravili greške. (We check contracts so as not to make mistakes.)

5. A noun instead of a clause: radi and zbog

When the goal is simply a thing or an activity, you can use radi + genitive, often with a verbal noun: Preselili su se u Beograd radi posla. (They moved to Belgrade for work.) Pohađam kurs radi usavršavanja. (I'm attending a course for further training.) In everyday speech zbog + genitive is also used this way: Došao je zbog potpisivanja ugovora. (He came for the signing of the contract.) radi is the one that means purpose only.

Do not confuse purpose with cause. jer and zato što give the reason something happened (cause, looking back): Nije došao jer je bio bolestan. da and kako bi give the goal (looking forward): Došao je da potpiše ugovor.