This article describes the usage and the formation of the illative plural, aka monikon illatiivi. The illative is used to express a movement towards or into a place (e.g. menen kirkkoon). The plural is used in phrases like Tutustun suomalaisiin ihmisiin (I get to know Finnish people) and Olen tottunut pimeisiin syksyihin (I’ve gotten used to dark autumns).

1. Use of the Plural Illative (mihin)

1.1. When saying TO or INTO

The illative has several different-looking endings (see below), but the meaning is usually quite clear: it means a movement into something or towards something or somewhere. In English you usually use “to” or “into”.

There can be some confusion with the allative, which also is translated as “to” in some cases. In general, the illative can be translated as “into”, while the allative is translated as “onto”. However, both will often be translated as “to”.

1.2. When using certain verbs

Finnish has this concept of “rections”: most words will require other words that they get combined with to appear in a certain case. There are several verbs that require mihin. Some examples are tutustua (to get to know), rakastua (to fall in love) and tottua (to get used to). You can learn more about verb rections here.

2. The Formation of the Plural Illative Case

The illative is one of the six location cases. It’s different from the other location cases for at least two reasons. First, its ending is added to the strong form of the word (learn more about consonant gradation for wordtype A here and for wordtype B here).

Second, the plural illative has several different endings, depending on the type of word you’re dealing with (-iin, -ihin, -isiin). All these endings have in common that they have the plural marker -i-.

2.1. Words ending in -u/-y, -o/-ö: add -i- + hin

2.2. Words ending in -ä: replace the -ä with -iin

2.3. Words ending in -a

I call the two groups of words ending in -a by the names “kissa-words” and “koira-words”. These two words are easy to remember and each belongs to a different group of words ending in -a. If you can remember “kissa – kissoihin” and “koira – koiriin” and apply that rule to other, similar words, you’re on your way to mastering the plural illative!

2.3.1. Words of two syllables (kissa-words): -oihin

Kissa-words are words of two syllables. Their final letter is -a. In the first syllable, you will have either -e-, -i- or -a-. In other words, the vowels of these words can look like:

• a…a (kana, maksa, sana, marja)
• e…a (herra, tela, teema, leija)
• i…a (kissa, tina, hinta, silta)

When you inflect these words in the plural illative, you will replace the final -a with -oihin.

2.3.2. Words of two syllables (koira-words): -iin

Koira-words are also words of two syllables. Their final letter is also -a. They differ when it comes to the first syllable: for koira-words you will have either –o- or -u- in the first syllable. In other words, the vowels of these words can look like:

• o…a (koira, konna, honda, nokka)
• u…a (kukka, sukka, suora, juoma)

For koira-words, you will replace the final -a with -iin.

2.4. Words ending in -i

Words ending in -i are once again divided into several groups. There are new words, which are often loanwords. There are also older, more Finnish words, which are inflected differently.

2.4.1. New words ending in -i: remove -i and add -eihin

2.4.2. Old words ending in -i: will end in -iin

These old words are usually nature words. They refer to things that have been around for centuries and have kept their old Finnish name.

2.4.3. Old words ending in -si: will retain their -si-, and end in –iin

2.5. Words ending in -e: add -isiin

2.6. Words ending in -nen: replace the -nen with -siin

2.7. One syllable words: replace the first vowel with -ihin

Words of one syllable can have a long vowel (e.g. maa, suu) or a diphthong (e.g. työ, suo). For these words, you will remove the first vowel of the word and add -ihin.

2.8. Words ending in two vowels: replace the last vowel with -isiin

2.9. Words ending in -jA: two groups

There are two groups of words ending in -ja/jä, which match up perfectly with the groups in the plural partitive. If there’s an -i- in front of the -ja/jä (e.g. opiskelija), the plural illative’s marker will be -oihin (opiskelijoihin). If there is another vowel in front of the -ja/jä (e.g. opettaja), the plural illatives’s marker will be –iin (opettajiin).

2.10. Words ending in a consonant

2.10.1. Words ending in -as: replace -as with -ai- and add -siin

Words ending in -as (or –äs, depending on vowel harmony rules) belong to wordtype B, so they will have the weak grade in their basic form (e.g. rakas, opas) and the strong grade in the illative (e.g. rakkaisiin, oppaisiin). Read more about words ending in -as here.

2.10.2. Words ending in -is: two groups

For words ending in -is, we have two groups. Words like kallis get -ii- when inflected, to which we add -siin. Words like roskis which get -iksi- when inflected, to which we add -in.

2.10.3. Words ending in -us/-os

Words ending in -os will get -oksi- when inflected (compared to -okse- in the singular). Words ending in -us get -uksi- when inflected in the plural. This means that in the plural, you won’t get the two groups of words ending in -us with different inflection. In the singular these words could belong to two groups: some get -uksi-, others get -ude-. You will want to check out this article to get the specifics. The plural forms all follow one rule.

2.10.4. Words ending in -ton: replace with -ttomi- and add -in

Read more about words ending in -ton here.

2.10.5. Words ending in –in: replace with -imi- and add -in

Read more about words ending in -in here.

2.10.6. Words ending in –ut: two groups

Words that end in -ut/yt can belong to two wordtypes. The smallest group of the two contains words such as olut, kevyt and lyhyt. These words have two possible plural illative forms: they either get -ihin or -isiin added to the basic form without the last letter.

The much larger group is made up of NUT-participles such as väsynyt and tottunut. For the words, you will replace the -ut/yt with -ei- before the plural illative’s case ending -siin.

2.10.7. Words ending in -tar

Words ending in -tar are rare, but at least tytär (daughter) is a common word. In the plural mihin-form, these words get -ttari- in place of the basic form’s -tar.

3. Consonant Gradation in the Plural Illative

The plural illative will always be strong, both for wordtype A and wordtype B.

I have a separate article on wordtype A.

I have a separate article on wordtype B.

That concludes the article on the plural illative case!

Related posts:

The Illative Case (Mihin) – S-Mihin – Finnish Grammar Location Case Verb Rections – Rektiot Missä Mistä Mihin The Plural Forms in Finnish – Examples