Apocopation in Spanish

Spanish has words which are shortened when they come before nouns. This is known as apocopation, the loss of one or more sounds from the end of a word. In Spanish apocopation often applies to adjectives. Here are examples:

David es bueno. (David is good)
David es un buen chico. (David is a good guy)

Este libro es mi primero. (This book is my first)
Es mi primer libro. (It's my first book.)

Francisco es el santo que amaba a los animales. (Francis is the saint who loved animals)
San Francisco es el santo de los animales. (Saint Francis is the saint of animals)

Manuel es mi tercero. (Manuel is my third)
Manuel es mi tercer hijo. (Manuel is my third child)

Quiero uno. (I want one)
Quiero un helado. (I want one ice cream)

A number of Spanish words are shortened when they come before a noun. The unstressed ending of the word is dropped. This ending always has the vowel /o/.