La apocopacion
Some adjectives drop the final o when the word that follows is singular, masculine
Antiguo
Old/ former before
antique/ old after
Cierto (a)
Certain before
True/correct after
Diferente
Various before
Different after
Grande
Great(gran) before
Big after
Mismo(a)
Same before
Self after
Nuevo (a)
Another, new to you, newly acquired, another before
Brand new after
Pobre
Poor, pitiful (emotion) before
Poor, no money after
Puro
Nothing but, sheer before
Pure after
Raro
Rare before
Weird after
Simple
Mere, just before
Simple, basic/easy after
Solo
Only 1 before
Alone, lonely after drop accent
Triste
Dreadful, pathetic before
Sad after
Unico
Only before
Unique after
Verdadero
Real before
True after
Viejo
Old, long-time before
Old, elderly after