Postpositions Govern the Genitive

English puts its little relational words in front of the noun — in front of the house, under the table. Finnish does the opposite: its equivalents come after the noun, which is why they are called postpositions rather than prepositions. And there is a second, non-negotiable rule that English gives you no warning about: the noun in front of a postposition must be in the genitive case. This page establishes that core pattern; the sibling pages handle the specific spatial words and the small minority that behave differently.

The template: [noun-genitive] + postposition

The building block of Finnish adpositional phrases is dead simple once you see it:

noun in the genitive + postposition

Look at the word order against the English. English: in front of the house. Finnish: talon edessä — the noun talon comes first, then the postposition edessä follows it. The relational word trails its noun. If you catch yourself writing edessä talon, you have imported the English order; flip it.

The genitive is the case that normally marks possession ("of"), and its ending is -n: talo → talon, kirja → kirjan. A postposition simply requires its noun to wear that ending. This is not optional or stylistic — a bare nominative in front of a postposition is a grammatical error, and it is the single most common mistake learners make here.

The genitive -n triggers gradation

Here is where beginners lose points even when they remember the genitive. Adding the genitive -n closes the final syllable of many words, and a closed syllable triggers consonant gradation — the stem consonant weakens. So the genitive is often not just "word + n"; the stem itself changes shape.

So pöytä ("table") does not give pöytän alla — the -t- weakens to -d-, giving pöydän alla. This gradation is exactly the same one you already meet in the ordinary genitive; the postposition just inherits it. The mechanics of t → d and the other gradation pairs are covered in full on the consonant gradation page.

Pronouns take a genitive and a possessive suffix

With a personal pronoun, you use the genitive pronoun (minun, sinun, hänen…) and — for the most common postpositions like kanssa ("with") — a possessive suffix on the postposition itself:

Minun kanssani is literally "my with-my" — the genitive pronoun minun plus kanssa plus the 1st-person suffix -ni. This double marking feels redundant to English speakers, but it is the standard shape; the possessive-suffix construction page treats it in depth.

Postpositions fill the gaps between the cases

You might wonder why Finnish, which already has a dozen local cases, needs postpositions at all. The answer: the cases cover the coarse spatial relations (in / on / into / onto / out of / off), and postpositions cover the fine ones the cases can't express — in front of, behind, under, between, around, beside. Where English uses one big undifferentiated pile of prepositions, Finnish splits the labour: broad relations to the case endings, precise ones to the postpositions. Together they form one coherent spatial system, which is why postpositions inherit the same three-way motion logic the cases have (covered on the three-way postpositions page).

A small minority behave differently

Not every Finnish adposition fits this mould, and it is worth flagging the exceptions so you are not blindsided:

• A few genuine prepositions exist and come before the noun, usually governing the partitive: ennen joulua ("before Christmas"), ilman rahaa ("without money"), keskellä yötä ("in the middle of the night").
• A handful of words work both ways — as preposition or postposition — with little change in meaning: keskellä katua ≈ kadun keskellä ("in the middle of the street").

These minorities get their own treatment on the partitive-governing adpositions page. For now, hold onto the dominant rule: postposition, after the noun, noun in the genitive.

Common Mistakes

Key Takeaways

• Finnish adpositions are mostly postpositions — they follow the noun, unlike English prepositions.
• The noun before a postposition must be genitive (-n): talon edessä, never talo edessä.
• The genitive -n often triggers gradation: pöytä → pöydän, kauppa → kaupan.
• With pronouns, use the genitive pronoun plus a possessive suffix: minun kanssani.
• A small minority are prepositions governing the partitive (ennen joulua) — the exception, not the rule.