1.- It's definite article 'le' is invariable. 

            2.- The singular noun can end in any vowel or consonant.
                 To form the plural are added the endings: 

                 '-s' (after vowel) or '-es' (after consonant).

             3.- Nouns that show living beings are epicene.
                  The sex affixes -in and -ul are used only if necessary.

             4.- The noun functions are expressed by prepositions and word order:

                  subject before verb and object after the verb.