Here's a summary of case forms for nouns and adjectives. Some cases are marked with an asterisk (*) meaning there is an explanation below the table.
This is the pattern for nouns in singular. The endings -a, -o, -e from nominative are replaced with other case endings, except where it's indicated that an ending is added to the nominative form (N +):
|noun type (N)||A||DL||I||G|
|-a (≈ fem.)||-u||*-i||-om||-e|
|neut. (≈ -o, -e)||= N||-u||N + m||-a|
|masc. not p/a||= N||-u||-om
The five rows above are declension types — groups of nouns having the same endings. Since three of them are very similar (neuter and masc.), Croatian declension is often described having three classes (e.g. I, II and III in some books). Which group a noun belongs to is based on its gender and nominative ending:
- all nouns in -a change in the same way (almost all are feminine, few are masculine, e.g. tata Dad)
- all neuter nouns change in the same way (they all end in -o or -e, but converse doesn't hold: e.g. some nouns in -o are masculine, and don't belong to this group)
- all masculine nouns that don't end in -a (they usually end in a consonant) belong to one of two groups, distinguished by their meaning
- all feminine nouns that don't end in -a (they usually end in a consonant) belong to the last group
Certain feminine nouns, ending in either -ka or -ga, end in DL in -ci and -zi, respectively:
Amerika America →
knjiga book → knjizi
The ending -em in the instrumental case is attached to nouns that end in a Croatian-specific letter, e.g.:
mrav ant →
konj horse → konjem
There are endings for adjectives:
|neut.||-o (-e)||= N||-om
|masc. not p/a||dict.||= N|
The default, dictionary form, as listed in dictionaries, usually has no endings, and is indicated with dict. in the table. It can have an optional -i, and some adjectives have always -i in masc. N, and they are listed so in dictionaries.
As for nouns, alternate endings that contain e instead of o in masc. and neut. genders are attached to adjectives ending on a Croatian-specific letter:
nov new →
loš bad → lošem
The e-endings also apply to all comparatives, even if they don't end in a Croatian-specific letter (e.g. širi wider).
Pay attention that alternative endings don't exist for the feminine gender.
The p/a in tables above stands for people and animals.
These are the endings for nouns in plural. The DL and I cases are identical in plural. There's an additional complexity for masculine nouns, see remarks below:
|noun type (N)||N-pl||A-pl||DLI-pl||G-pl|
|-a (≈ fem.)||-e||= N||-ama||*-a|
|neut. (≈ -o, -e)||-a||= N||-ima||-a|
|masc.||*-i||*-e||N + ma||*-a|
|fem.||-i||= N||N + ma||*-i|
Most short (one-syllable) masc. nouns ending on a consonant have either ov or ev inserted before the endings listed above. For some masc. nouns there's a consonant alternation in N and DLI.
Details are described in 29 Plural of Masculine Nouns and Adjectives.
The genitive case in plural has many exceptions that get rather -i instead of -a. Additionally, some nouns get lengthened by inserting an additional a or by using the nominative form instead of their case-base:
Details are described in 44 Genitive Plural.
There are endings for adjectives in plural; forms for DLI and G are the same for all genders:
Adjectives that end in -j in N masc. sing. cannot get an optional -i. All such adjectives have specific meanings, e.g. taj (t-) this.
Possessive adjectives moj my, tvoj your and svoj have double forms in masc. (m) and neuter genders in singular:
When an adjective is used as a noun or pronoun, it gets an additional -a in DLI-pl:
Na mladim ljudima svijet ostaje. The world is left to the young people.
Na mladima svijet ostaje. (the same meaning)