kako bi vs da (so that / in order to)

"I'm studying so that I'll pass", "I gave you money to buy bread", "I'm going to buy bread" — English bundles purpose into a few interchangeable frames built on to and so that. Croatian has three distinct constructions, and they are not freely swappable: each suits a different subject configuration and register. da + present is the everyday purpose clause, especially when the purpose has a different subject. kako bi (or da bi) + l-participle is the "so that / in order to" of careful and written Croatian, and the natural choice for same-subject purpose. And after a verb of motion, Croatian often uses a bare infinitive. This page lines all three up so you can pick the right one without thinking.

The quick test

da + present — the everyday purpose clause

The most common purpose construction is simply da + a present-tense verb. It is neutral in register and works for any subject, but it is the only option when the purpose has a different subject from the main verb — because a da-clause can carry its own subject, while an infinitive cannot. "I gave you money so you buy bread" has two subjects (I give / you buy), so da is obligatory.

This is the same da that introduces the different-subject clause after volition verbs, and the logic is identical: no shared subject means no infinitive. That parallel is laid out on da + present vs the infinitive. When the subject is shared, da + present is still possible and common in speech (Učim da prođem), but for the explicit "in order to" of writing, Croatian reaches for the next construction.

kako bi / da bi + l-participle — in order to / so that

For the deliberate "in order to" — purpose stated as a goal, especially in writing and especially when the subject is the same throughout — Croatian uses kako bi (or da bi) followed by the l-participle (the same past-participle form used in the conditional). The auxiliary bi here is the conditional auxiliary, and it agrees with the subject: kako bih (I), kako bi (you/he/she), kako bismo (we), kako biste (you pl.), kako bi (they).

The form to watch is the agreeing auxiliary: it is kako bih with a first-person subject and kako bismo with "we", not an invariant kako bi in every person. This mirrors the conditional auxiliary exactly — see Conditional I for the full bih/bi/bismo paradigm. Da bi + l-participle is an equally correct variant of the same construction (Učim da bih prošao); kako bi tends to feel slightly more formal and unambiguous. Both belong with the other subordinators.

The bare infinitive — after motion verbs

After verbs of motion — ići (go), doći (come), trčati (run), vratiti se (return) — and a few others, Croatian very naturally expresses the purpose with a bare infinitive, no da and no kako bi. This is the crispest of the three and the default in speech when you move somewhere in order to do something.

The bare infinitive only works when the subject is shared (you go, and you also buy) — exactly the configuration where it is allowed at all. If a different person is to do the buying, you fall back to da: Idem da mi kupiš kruh would be wrong; you would say Idem po kruh or recast it. For the broader infinitive-vs-da picture, again see da + present vs the infinitive.

All three side by side

Three framings of "buy bread", three constructions — because the surrounding sentence differs in subject and register. The motion verb pulls the infinitive; the different subject forces da; the stated goal in careful style invites kako bih.

Common Mistakes

Key Takeaways

• da + present is the everyday purpose clause and the only option when the purpose has a different subject: Dao sam ti novac da kupiš kruh.
• kako bi / da bi + l-participle is the "in order to / so that" of writing and same-subject purpose, with the auxiliary agreeing with the subject: Učim kako bih prošao, Štedimo kako bismo putovali.
• A bare infinitive is the natural purpose form after verbs of motion with a shared subject: Idem kupiti kruh.
• Choose by subject and register: different subject → da; same-subject deliberate goal in careful style → kako bi (agreeing); motion verb → infinitive.