You may want to support further development of this grammar overview by donating via PayPal (you do not need a PayPal account):

S

3.1 Case and number

Esperanto has no grammatical gender.

There are two numbers – singular and plural. Singular has no ending, plural is expressed by the ending j added to the basic form of the word.

singular
amiko friend
plural amikoj friends

Regarding the form, there are two cases – nominative and accusative. Nominative has no ending, accusative is expressed by the ending n added to the word in the proper number.
nom. sg. bela domo nice house
acc. sg. belan domon nice house
nom. pl. belaj domoj nice houses
acc. pl. belajn domojn nice houses