Nouns are one of the most important parts of Lithuanian grammar. They are words that represent people, objects, places, or ideas, and they play a crucial role in sentence structure.

In Lithuanian, nouns are highly inflected. This means that they change their form to indicate different grammatical features such as gender, number, and case. There are three genders in Lithuanian: masculine, feminine, and neuter. Nouns also have two numbers: singular and plural.

Lithuanian nouns can be declined into seven cases: nominative, genitive, dative, accusative, instrumental, locative, and vocative. Each case has its own form and is used to show the relationship between the noun and other words in the sentence.

In addition, Lithuanian nouns have different declensions depending on their ending or stem. There are six declensions in total, each with its own set of rules.

Learning the rules and patterns of Lithuanian noun declension can be quite challenging for non-native speakers. However, a solid understanding of noun theory is essential for mastering the Lithuanian language and effectively communicating in both spoken and written form.