Transitivity and intransitivity

1. Use

The matter of when to use a transitive or an intransitive verb is complicated for most foreigners. You often use a different verb for both in Finnish.

To transitive verbs we count verbs that have an object. (Avasin oven. I opened the door. oven=object). Intransitive verbs don't have an object. (Ovi avautui. The door opened itself. ovi=subject). As you see, a transitive verb's object can become an intransitive verb's subject.

Intransitivity isn't the same as passivity. Passive sentences can have an object, but not a subject. In intransitive sentences there is a subject, but it can never be an object. Often, translating the sentence to English will make the intransitive sentence passive.

Transitive sentence (with an object) Intransitive sentence (with a subject)
Vaihdoimme laukkuja. Laukut vaihtuivat.
= We changed the bags. = The bags were changed.
Näen jo rannan. Ranta näkyy jo.
= I see the beach already. = The beach is already visible.
Olen jo unohtanut tapauksen. Tapaus on jo unohtunut.
= I've already forgotten the event. = The event is already forgotten.

2. Formation

There are several groups of intransitive verbs.

2.1. -u/-y

The most common ones are the verbs where an -u/-y is added.

Transitive Explanation Intransitive Explanation
vaihtaa to change vaihtua to be changed
löytää to find; to discover löytyä to be found; to be discovered
murtaa to break (actively) murtua to be broken
nähdä to see näkyä to be seen; to be visible
unohtaa to forget unohtua to be forgotten
innostaa to inspire innostua to become inspired
kaataa to pour (to "make fall") kaatua to fall
jatkaa to continue jatkua to be continued
kuulla to hear kuulua to be heard; to be audible
yhdistää to unite yhdistyä to be united
valmistaa to complete valmistua to be completed

2.2. -utu/-yty

Intransitive verbs with -utu/-yty are usually a bit different from the ones above. The intransitive one often means "to do something to oneself". In these cases, you can use the transitive one as well, when you add "itse" behind it: "Minä pesen itseni." is the same as "Minä peseydyn." "Itse" would be the object in a sentence, something that is not allowed for the intransitive verb.

Transitive Explanation Intransitive Explanation
korjata to fix korjautua to be repaired
lykätä to postpone lykkäytyä to be postponed
pestä to wash something peseytyä to wash oneself
pukea to dress pukeutua to dress oneself
valmistaa to prepare valmistautua to prepare oneself
sitoa to bind sitoutua to bind oneself; to commit oneself

Sometimes, there is an alternative for the -utu/-yty intransitive verbs: -ntu/-nty, like in "haaraantua" or "jakaantua".

2.3. Intransitive basicwords

There are also verbpair whose relationship is opposite: the basic verb in intransitive (pudota), and therefrom a transitive verb is derived (pudottaa).

Intransitive Explanation Transitive Explanation
pudota to fall pudottaa to drop
kadota to be lost kadottaa to lose
saastua to be polluted saastuttaa to pollute
selvitä to become clear selvittää to clear up
herätä to wake up herättää to wake (someone) up
hukkua to be drowned hukuttaa to drown
kasvaa to grow kasvattaa to raise