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