Croatian verbs have two grammatical aspects; the perfective and imperfective. The perfective aspect depicts an action that has already been finished or done with. The imperfective aspect depicts an action that is still going or underway. So, each verb in its infinitive form can be written in 2 ways; in its perfective and imperfective aspect. The table below is showing 5 verbs both in their perfective and imperfective aspects.
| Imperfective aspect in infinitive | Perfective aspect in infinitive |
| Trčati. (To run. – infinite action) | Odtrčati. (Definite action, the running has been done with.) |
| Sjediti. (To sit. – infinite action) | Sjesti. (-||-) |
| Plivati. (To swim. – infinite action) | Odplivati. (-||-) |
| Graditi. (To build. – infinite action) | Izgraditi. (-||-) |
| Popravljati. (To fix/repair/mend. – infinite action) | Popraviti. (-||-) |