In Finnish, it is easy to get essive and translative cases mixed up, because both are related to the state or role of something/someone. The main difference is whether it is a permanent state or a change.

The essive ending is -na/-nä and it answers the question “in what state” / “as what like”. The ending -na/-nä is used with static verbs like olla, työskennellä, pysyä.

The translative ending is -ksi and it answers the question “(in)to what state” / “to what like”. The ending -ksi is used with dynamic verbs like opiskella, hakea, tulla.

 

-na/-nä is the essive ending, and it is used to describe a momentary state in which someone/something is right now.

Vaimo on raskaana.
The wife is pregnant.

Pää on ollut kipeänä pari päivää.
My head has been aching for a couple of days.

Pysy terveenä!
Stay healthy!

 

The translative ending -ksi is added when emphasizing a change, transition from one state to another.

Vaimo tuli raskaaksi.
The wife got pregnant.

Pää tulee kipeäksi.
The head gets sore.

Tulin iloiseksi, kun sain sen työpaikan.
I became happy when I got that job.

 

When you want to say which role you work in or what your title is, use the ending -na/-nä:

Meeri työskentelee lääkärinä.
Meeri works as a doctor.

Olen siivoojana toimistossa.
I work (lit. am) as a cleaner in an office.

 

If you are a student or about to change careers, use the ending -ksi to tell what you will become when you grow up.

Meeri opiskelee lääkäriksi.
Meeri studies to become a doctor.

Haen siivoojaksi hotelliin.
I’m applying to be a cleaner at a hotel.

 

The ending -na/-nä is also used in time expressions, for example with the words viime, tänä, ensi.

Mitä teit viime viikonloppuna?

En ole töissä ensi perjantaina.

 

The ending -ksi is used when expressing the time by which something will happen or for how long it will happen.

Palaveri on maanantaina. <> Projekti on valmis maanantaiksi.
The meeting is on Monday. <> The project will be ready by Monday.

Menen kolmeksi päiväksi Helsinkiin.
I’m going to Helsinki for three days.

Kaveri tulee yöksi kylään.
A friend is coming to stay for the night.

 

When the ending -ksi is added to the stem of a word, the KPT changes will occur. When the ending -na/-nä is added to the stem, there are no KPT changes.

Menen mökille viikonlopuksi. <> Menen mökille viikonloppuna.
I’m going to the cottage for the weekend. <> I’m going to the cottage at the weekend.