Definite articles (in English, the) are used with nouns to indicate specific persons, places, or things. Indefninte articles (a, an) are used with nouns to indicate nonspecific persons, places, or things.

All Spanish nouns, even if they refer to objects, are either masculine or feminine.

• Nouns ending in -o are usually masculine.
• Nouns ending in -a are usually feminine.
  

Los libros son para la maestra. --->The book are for the teacher.

To form the plural of a noun, add -s  if the nouns ends in a vowl.  Add -es if the noun ends in a consonant.

estudiante --> estudiantes             mujer --> mujeres