Verbs can be transitive (перехідні́) or intransitive (неперехідні́), depending on whether or not they require an object to express a complete thought. Most verbs are transitive. They direct their action towards the object.

Examples with transitive verbs:

Я чита́ю кни́гу. – I read a book.
Я відкрива́ю раху́нок. – I open an account.
Я вивча́ю украї́нську. – I am learning Ukrainian.
Я ми́ю мою́ тарі́лку. – I am washing my plate.

The following verbs belong to intransitive group:

1. Reflexive verbs, the verbs ending in “-ся”, “-сь”: усміхатися (to smile), умиватися (some verbs can come from transitive form “умивати – умиватися” – to wash);
2. impersonal verbs denoting the state of nature or man: дощить (it rains);
3. verbs with the meaning of moving in space: іти (to go), летіти (to fly), бігти (to run), etc.

Examples with intransitive verbs:
Він сміє́ться. – He is laughing.
Вона́ посміха́ється. – She is smiling.
Вони́ біжа́ть. – They run.
Йде сніг. – It snows.
Вони́ готу́ються до екза́мену. – They are preparing for the test.

Most of intransitive verbs end with the particle “-ся”, “-сь”. If a verbs requires a preposition to connect with a noun in accusative case it is an intransitive verb.

Сіда́ти в маши́ну. – To get in the car. (Lit. to sit in the car)

Note: Sentences with an intransitive verb cannot be changed into passive voice.

There are a few verbs which can be transitive and sometimes intransitive depending on a situation.

Він малю́є карти́ну. – He paints a picture. (transitive)
Він га́рно малю́є. – He paints well. (intransitive)