Word endings (noun cases) and word changes (declension)

Most of you have probably heard that “Finnish doesn’t have prepositions”. Actually, that’s not entirely true, but it is true in spirit. As we discussed, Finnish is a syntethic language, and instead of using prepositions (modifier words), it directly attaches suffixes to the words they modify. So instead of saying in the house, one would say talo-ssa with equivalent meaning. When they are added to the words, there are two main parts:

  • First, you have to know what suffixes to use. This is hard, because there isn’t a one-to-one mapping of usage to other languages. However, prepositions are always hard in other languages because there never are one-to-one maps, so this is normal.
  • Second, suffixes aren’t directly, attached, there can be changes in the base word. This may seem difficult at first, and it does take some getting used to. However, as in most things in Finnish, it ends up being quite logical.

Mentally, there are two main thing you need to be able to do quickly:

  • First, you have to be able to apply endings to words. This is both knowing what to use, and how to do the word changes.
  • Second, and maybe not as obvious, is being able to look at a word and discover the base and extension(s). This is hardly ever mentioned, but actually does require some practice. To read Finnish easily, this needs to be automatic. When reading a new word, you should read from beginning to end and end to beginning at the same time.

Glossary: The base form is the nominative: what you look up in a dictionary. The stem is a modification (inflection) of the base form to which extensions can be attached. Our main concern now is locative cases of nouns.

The noun case endings

There are different types of endings that can be applied to nouns: the basic noun cases, particles that have some sort of emphasis, and many other types. We are mainly focused on the noun cases right now.

Below, you can see the table of the basic endings. There are more, and we aren’t going to try to explain them right now — you’ll learn them them in real courses. For now, we are just looking at the overall patterns.

  Name ending meaning how used
  Nominative - basic form (this is the base form)
  Genitive -n possessive or object closed (weak)
  Partitive -a, -ta, -tta part (attached to base form)
  Illative -Vn to inside open (strong)
  Inessive -ssa inside closed (weak)
  Elative -sta from inside closed (weak)
  Allative -lle to closed (weak)
  Adessive -lla on, by closed (weak)
  Ablative -lta from closed (weak)
  Nominative plural -t basic form plural closed (weak)
  Plural -i- + other ending plural depends on other ending

We see three main categories: The nominative is the base form of a word. and the partitive uses the base form (which is usually strong). The Illative uses the strong form of the word. Most most others use the weak form. The main point of this chapter is learning how to apply these endings to words, and the strong/weak question is the most important thing for that.

There are more endings which we aren’t discussing now, but just realize they exist and fit in the same pattern as above:

  • Possessive suffixes: -ni (my), -si (yours), -mme (our), -nne (yours, plural), -nsa (his, hers, their, singular or plural). These take the … form. TODO
  • Enclitic Particles: -ko, -han, -pa. These convey some mood or emphasis in speaking. TODO
  • … and more. TODO

Remember vowel harmony! In a word without (a, o, or u), we get the changes (a→ä, o→ö, and u→y) in all suffixes. It is so predictable it’s not even worth writing both forms, so I don’t.

Reminder: syllable formation

Let’s review something from a few chapters ago: syllable formation.

Summary: Syllables start at every consonant before a vowel, and between vowels that don’t form a dipthong. So a word might be segmented this way: kvk·kv·kv.

A syllable kv is open, and a syllable kvk is closed. If a single k is added to an open syllable, it becomes closed: kv + -kkvk. Same with kv + -kkvkvk·kv.

A long vowel (the same vowel letter twice in a row) also effectively makes a syllable open regardless of what is at the end. So -kaan is open, but -kan and -kain (dipthong) are not. TODO: dipthongs too?

Consonant gradation

Finnish has a concept called consonant gradation. It is almost exactly what it says: the consonant changes between two grades, strong and weak. Strong consists of something harder (e.g. p), and the weak consists of something softer (e.g. pv) of somewhat similar sounds.

As with everything in languages, there’s no single reason for this. But you can consider it as somehow making the language flow better: when a syllable is open at the end of the word, it can take more emphasis at the beginning. But when it becomes closed, it takes something softer to make it flow better.

The following are the basic consonant gradation patterns in Finnish (there are a few more, but they are infrequent enough so you’ll learn them as you need them.)

Strong (open) weak (closed)
k _ (is removed)
p v
t d
kk k
pp p
tt t
nk ng
mp mm
nt nn
lt ll
rt rr

So, for example, we have ka·tu + -tka·dut, and tuk·ki + -ntu·kin.

The patterns st, sp, sk, and tk never change.

Many students consider consonant gradation as annoying. However, they are simple if thought of in terms of open and closed syllables. In fact, it is best to not think of these as being word changes: imagine that words exist as a quantum superposition of both forms occurring at the same time. You see one particular form written down depending on if it is observed in an open syllable or closed syllable, and you mentally write down whatever is needed in each case.

Primarily, consonant gradation happens in the last syllable of the word, depending on what ending is applied: if it’s a closing ending (-t, -n, -ssa, etc) you get the weak form, and otherwise the strong form.

Secondarily, it can happen before the last syllable, but only when there are changes that have effects that open or close a syllable. So, you make a change at the end which happens to open or close the second to last syllable (you’ll see these in the next section).

A syllable that has a long vowel (two of the same in a row) in it is always open: imagine that the long sound insulates the front from the back of the syllable. This leads to words where consonant gradation should apply, but is always in the strong form.

You have to be able to do both forward consonant gradation (a syllable closes) and reverse consonant gradation (a syllable opens).

Stems from basic forms

If you have a word like pu·he·lin (phone), you can’t just add an ending like -n to it because it would break the syllable pattern (two consonants at the end of a syllable). So, before you can add endings, every word is converted to some form that ends in a vowel.

The base form is the nominative, and the inflectional stem is the form which most endings are added to. The inflectional stem can be observed in both strong and weak forms. The inflectional stem is the same as the base form when it’s already suitable for adding stems (such as when it ends in a vowel).

A word like talo (building) is directly able to take any ending: the base form is the same as the stem.

Examples of stem changes


Below are various examples below for your information not memorization. For now just look at the general patterns. You will learn these as you go through your regular lessons, and as you do it will make a lot more sense. For now, just focus on the stem changes and what it does with consonant gradation.

-i-e (oviove-). Why? Because -i- is for plural, so basically everything gets changed to -e- for singular, except some modern loanwords.

-as-aa (vie·rasvie·raa-). A similar thing can happen with -is. This unconditionally opens the last syllable (because of the long vowel) causes reverse consonant gradation (a·su·kasa·suk·kaa-) in all forms: it doesn’t matter what stem is attached, unlike the normal case where the stem affects the gradation.

-nen-se- (nai·nennai·se-). You can try to rationalize this by imagining the n becomes s and the last n removed. This is a very common pattern.

-in-ime- (pu·he·linpu·he·li·me-). In this case n becomes m which makes you somehow think of consonant gradation, and e is added.

-us-uske- (vas·tausvas·tau·kse-). A k appears out of nowhere, which is actually reverse consonant gradation so it sort of makes sense. An e also is added.

-e-ee- (ha·meha·mee-), which also causes reverse consonant gradation like the -as case because it unconditionally opens the last syllable syllable (because of the long vowel). For example kaa·dekaa·tee-.

There are lots of different words that end in -i. Most of them become -e- in the stem, but new loanwords stay as -i- (new loanwords generally don’t obey old patterns). There are also “old Finnish words” that have a different category: partitive is different (pieni + partitive → pientä). So, when understanding -i words, classify them into three categories: very old Finnish words, Finnish words, and modern loanwords. You will learn this during your studies of Finnish.

These are just some examples, and show you what to expect. We don’t come close to explaining how to use all the different cases, use a proper class for that!

There are many different types of stem changes, but most fit into some major categories. KOTUS (the Finnish language standards body) classifies them into about 50 different types, but there is a lot of effective duplication based on exact letters and forward/reverse consonant gradation: however, in effect, many of these differences can be understood based on the rules described above, so the effective amount you have to learn is a lot smaller. Wiktionary has a list of Kotus types, but I don’t think the list is that accurate or useful: however, wiktionary is good if you know a word and want to know it’s inflection, or vice versa. Also, be aware that there is not universal agreement on the numbering of the types.

Forming new words with endings

After the above is known, it’s fairly easy to form the endings.

Partitive adds -a to base words that ends in one vowel, -ta to words that end in one consonant or a long vowel, and -tta to a word that ends in -e. Why the special e? It used to be a different type of sound, so is treated specially. You notice that e is special very often. Some words have a partitive form derived from something else.

The illative adds -Vn to stems that end in a single vowel (V represents a doubling of the previous vowel), -hVn to a stem that ends in two vowels. All of these cause the strong form to appear.

Most of the other stems are just added, and consonant gradation is applied if needed.

When learning a new ending, the two important things to learn are: is it applied to the base form or stem, and does it close the last syllable (strong or weak)?


To form plural words, the basic rule is to add an -i- to the stem, then whatever other ending. It seems more complicated because of some rules, but they are actually quite standard.

There can be vowel changes in partitive: For example vivvjv (v=a vowel). These vowel changes add another level of complexity, but are mostly mechanical.

Double vowels become a dipthong: vv + -i-vi (vv=same vowel twice).

Diphtongs mutate: ie + -i-ei. uo + -i-oi. + -i-öi.

Even though this plural may add a dipthong (vi), it always acts as a single vowel so consonant gradation can still happen depending on the endings (TODO: is this correct?).

There are lots of other complexities, but you can understand them based on what is in this chapter plus a few more rules.

Overall diagram


Insert diagram here:

Base form. → Partitive can form from base

⇅ (inflect)

Inflectional stem. (Quantum superposition strong/weak forms) → nominative plural, all other forms.

⇅ (add -i-)

Plural inflectional stem (strong/weak). → All other forms.


Don’t be afraid! It’s probably impossible for this to make sense right now, but think/come back to this as you start studying Finnish and suddenly all the word changes will start making a lot of sense.

Remember, it is best to not think of consonant gradation as a real change of the word. The word stem exists in both formats simultaneously, and you happen to observe it in strong or weak form depending on if it is closed or open.

The genitive is seen as the prototype “stem in weak form” (if you know genitive, you know everything). So, you will often be told “take the genitive and remove -n to make other forms”. This just means “we use the inflectional stem in weak form”. You see the same thing in other cases: -vat removed from verbs to represent verb stem in strong case, or -n removed from verbs to represent verb stem in the weak case. Think of the stems!

Really, for singular, if you know the nominative (base) and genitive (-n), you know 90% of how to make all words. If you know nominative, genitive (-n), partitive (-a, -ta, -tta), and illative (-Vn), you know how to use 99.99% or 100% of all forms of all words words. A similar thing can be said for plural. So, the amount you actually have to know is much smaller than you might expect. Also, the rules of this chapter can handle 98% of all the changes.

There are different complexities, but can still be understood in this framework. For example, -ton looks like it’s doesn’t close the syllable, but actually it does. This is because of historical reasons: originally the suffix was -ttojn, which would close the word. So, in this case, you don’t remember -ton stems, you remember “-ton closes the stem”.

There are other changes, such as uku to uvu and yky to yvy. These are much more rare, but you will learn about them later.

There are also occasional vowel changes, because you can’t have too many vowels in a row. For example, i becomes j between other vowels. So, you get more complex things like aika + -naikanaianajan.

In addition to the complexity of remembering all of these, it can also just make general awareness of the language harder. It can be easy to remember maito + -nmaidon, but if you are just quickly reading and you see maidon, it looks like a much different word from maito! It takes a lot of internalizing to make all of the connections.

It also takes some practice to resolve ambiguity: In a word, would t become d (consonant gradation), or tt (reverse consonant gradation)? It takes practice and experience to keep all the word changes between all the different endings straight. k is especially annoying: it disappears in the weak form, so words can look especially different. When there is reverse consonant gradation, it can seem to appear out of nowhere!