The basic form of a noun is called the nominative case.
This form you will find in dictionary. It is a basic form of a noun.
The basic question for this word is KTO? (who?), question for a person: MAMA, TATA, NAUCZYCIEL, PROFESOR, RALUCA, MIREK and CO? (what?), question for a thing: BIBLIOTEKA, STÓŁ, KSIĄŻKA, RĘKA
EXAMPLES IN THE SENTENCES:
1. Nominative is a SUBJECT of the sentence:
Mirek jest w bibliotece. Biblioteka jest ładna.
(Mirek is in the library. Library is nice)
2. Affirmative sentences THIS IS X.
- To jest biblioteka.
- To jest Raluca.