The Final Construction: mennäkseni

To say "in order to" — to name the purpose behind an action — Finnish can fold a whole purpose clause into a single inflected word. This is the finaalirakenne, the "final construction" (from Latin finis, "goal", not "last"). It is built on the long first infinitive: the dictionary form of a verb, plus the translative marker -kse-, plus an obligatory possessive suffix that agrees with the subject of the main clause: Menin kauppaan ostaakseni maitoa "I went to the shop in order to buy milk." This page treats the construction as a clause — what it replaces, when it is allowed, and how it competes with the jotta-clause and the -maan infinitive. For the pure morphology drill (harmony, the third-person -kseen), see the long first infinitive page.

What it is: a purpose clause in one word

Underlyingly, ostaakseni maitoa is a full subordinate clause — "so that I may buy milk." Finnish compresses it: the finite verb and the conjunction vanish, the verb becomes the -kse- infinitive, and the subject survives only as the possessive suffix. The construction answers the question "what for?"

The possessive suffix set is -kseni, -ksesi, -kseen, -ksemme, -ksenne; the third person is -kseen for both hän and he. The suffix does not choose freely — it is controlled by the main-clause subject, so Menin forces -kseni and Hän säästää forces -kseen.

The one hard rule: same subject only

The finaalirakenne is a shared-subject construction. One actor performs the main action and the intended purpose. In Menin kauppaan ostaakseni maitoa, I went and I buy — one subject, so the possessive -kseni is legal and points back to that subject.

The moment the purpose belongs to someone else, the construction collapses. English happily says "I gave him the key so that he could get in," but Finnish cannot pour a different actor into the -kse- form, because the possessive suffix has no separate subject to attach to. There you must switch to a finite jotta-clause with a conditional verb:

The full comparison of same-subject versus different-subject purpose lives on purpose and result clauses.

The jotta paraphrase

Every finaalirakenne can be unpacked into a jotta-clause with a conditional verb, and the pairing is the best way to feel what the compressed form is doing:

Because the subject is shared, both versions are grammatical; the -kse- version is simply tighter and reads as more written. Note that the jotta-clause routinely uses the conditional (ostaisin, läpäisisin, voisin), which is exactly the nuance the compact form absorbs into itself.

Object case inside the construction

The -kse- infinitive still takes an object, and that object behaves like any verb's object: a bounded, complete object goes in the total (accusative -n) form, an unbounded or partial one in the partitive.

In lähettääkseni paketin the parcel is a single complete thing (total object paketin); in join kahvia the coffee is an unbounded amount (partitive kahvia). The purpose construction changes nothing about the ordinary rules of the object case.

The finaalirakenne versus -maan after motion verbs

Here is a subtlety worth its own section. After a verb of motion (mennä, tulla, lähteä), everyday Finnish often expresses the goal of the movement with the third infinitive -maan rather than the -kse- form:

Menin ostamaan maitoa (informal, neutral) and menin ostaakseni maitoa (formal, written) both mean "I went to buy milk." The difference is register and reach:

• -maan is idiomatic and light, but it only works after verbs that license it — mostly motion and a handful of others (jäädä, tottua). It says "went to do."
• -kse- works after any main verb and always reads as more formal. When the main verb is not a motion verb, -maan is impossible and the finaalirakenne (or a jotta-clause) is your only option:

Two limits and one fixed expression

It is affirmative only. You cannot negate the finaalirakenne. "In order not to be late" needs a finite clause: Lähdin ajoissa, jotta en myöhästyisi "I left in time so as not to be late," or ettei: …, ettei tulisi myöhä.

It is formal and written in tone (formal / literary). It is everywhere in the news, essays and literature; in casual speech Finns lean on -maan, jotta, or sitä varten että. A handful of -kse- forms have hardened into fixed sentence adverbials, though: ymmärtääkseni "as far as I understand," tietääkseni "as far as I know," nähdäkseni "as far as I can see," ollakseni rehellinen "to be honest." These you will hear even in relaxed speech.

Common Mistakes

Key Takeaways

• The finaalirakenne = first infinitive + -kse- + possessive suffix and means "in order to." It compresses a same-subject purpose clause into one word.
• The possessive suffix is controlled by the main-clause subject: Menin → -kseni, Hän → -kseen (also he → -kseen).
• Same subject only. A different purpose-doer forces a jotta-clause with a conditional verb.
• After a motion verb in speech, -maan is the everyday rival (menin ostamaan); the -kse- form is the general, formal option and the only one available after non-motion verbs.
• It is affirmative-only and formal/written, apart from fixed adverbials like tietääkseni and ollakseni rehellinen.