Plural forms of Spanish nouns

Following are the rules for plural Spanish nouns.

1. Nouns ending in a vowel form their plural by adding -s:
   el alumno         los alumnos        (student)
   el presidente    los presidentes   (president)
   el amigo           los amigos         (friend)
   la muchacha     las muchachas   (girl, maid)
    
2. Nouns ending in a consonant form their plural by adding -es:
   el papel          los papeles     (paper)
   el doctor        los doctores   (doctor)
   la flor             las flores        (flower)
    
3. Nouns having a written accent on the last syllable lose the written accent in the plural:
   la nación             las naciónes    (nation)
   la composicion    las composiciones (composition)
    
4. Nouns ending in -z in the singular change z to c before adding -es in the plural:
   el lápiz                los lápices  (pencil)

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