Characteristics of the Estonian language in AX Semantics


In Estonian, you need to know the number of a noun to form the accompanying adjectives, determiners and pronouns correctly.

Estonian has no gender for nouns. There are two numbers: singular and plural. Additionally, Estonian has fourteen cases for nouns.

grammatical namevaluesexamples
numbersingularüks vana auto
(one old car)
pluralviis vana autot
(five old cars)
cases (noun)nominativemaja (house)
genitivemaja värvus
(house's color)
partitiveMa värvin maja.
(I'm painting the house.[part/incomplete object])
essivekasutada laagrit majana (use the camp as the house)
translativeMa muudan selle majaks.(I'll turn it into a house.)
terminativeSiit on majani 2 km.
(From here it's 2 km to the house.)
adessiveKohtumiseni majal!
(See you at the house!)
ablativeMa kõndisin sellest majalt teise.
(I walked from the house to another.)
allativeMillal te majale saabute?(When will you be arriving to the house?)
illativesiseneda majja
(walk into the house)
elativejalutuskäik majast
(walk from the house)
inessiveMa elan majas.
(I live in the house.)
abessiveIlma majata on raske elada.
(It's difficult to live without a house.)
comitativekoos oma majaga
(with his house)
adjectives (noun)before nounpunane õun
(red apple)
verb tensespresentta ostab
(he buys)
pastta ostis
(he bought)

The standard order of a noun phrase in Estonian is the following:

preposition + determiner + numeral + adjective + noun

See for example:

ilma     nende  kolme   populaarse lauljata
without  these  three   popular    singer[sg,part]
PREP     DET    NUM     ADJ        NOUN
"without these three popular singers"



Estonian nouns are inflected for number and case. Lexicon entries for nouns may also be necessary for inflecting determiners, adjectives and pronouns correctly. They are omitted, if a lexicon entry is required, but missing.


The basic lexicon entry for maja (house) contains:

  • inflection table for case and number:


If you need lexicon entries for countries, write to the support about that and you will get them for Estonian with automatic handling of prepositions.


In the lexicon, the inflection table encodes case and number. For adjective position, the default is "before noun".

Adjectives are automatically taking the genitive form when the accompanying noun is in terminative, essive, abessive, or comitative case. For example:

kollane maja (a yellow[nom.] house[nom.])
kuni kollase majani (as far as a yellow[gen.] house[term.])


Estonian verbs inflect for person, number and tense. The most common verbs are encoded in our software. If a verb inflects incorrectly, you should add it to the lexicon.

Container settings


The AX NLG platform supports the following determiners for Estonian: demonstrative, distal, possessive, and quantifier (every). Similar to the case agreement for adjectives, determiners automatically take the genitive form when the accompanying noun is in terminative, essive, abessive, or comitative case.


The noun will automatically agree with the numeral number when a numeral variable is used. Four types of numerals are possible on the AX NLG platform: cardinal, cardinal as digit, ordinal, and ordinal as digit.

As the example below shows, cardinal numerals other than 1 require the partitive case in the singular number for the (adjective and) noun that follow (e.g. päeva).

textüheksa päeva
(nine days[par.])
üheksas päev
(the ninth day)
digit9 päeva
(9 days[par.])
(the 9th day)

Notice when numerals accompany an adjective and a noun, they are all in singular form:

punased autod[]
(red cars)
kaks[sg.nom.] punast autot[sg.part.]
(two red cars)

For Estonian, both cardinal and ordinal numerals are written out until 10 on the platform, otherwise (above 10) the output is in digit form. Take cardinal numerals for example:

kümme autot
(ten cars)
11 autot
(11 cars)


Estonian prepositions normally require the noun to be in the partitive or genitive case, for example, üle (over), mööda (along), etc.

Mine üle silla[gen].
(Go over the bridge.)
Ma kõnnin mööda tänavat[par].
(I am walking along the street.)

Estonian uses both pre- and postpositions. In Estonian containers, only prepositions can be set, postpositions have to be put after the container as plain text.

Consonant gradation

The AX platform applies consonant gradation in Estonian automatically. This means that consonants alternate between a strong grade (e.g. kk/pp/mb/…) in some inflection forms of a word and a weak grade (e.g. k/p/mm/…) in others. It can only take place at the border between the last and the one-but-last syllable.

The following example shows a consonant gradation from ss to s (strong to weak):

kirss (cherry, nom sg) -> kirsid (cherries, nom pl)