(in your judgement)
(^) una casa pequeña a small house
(a fact – the house is small)
The rules about the position of adjectives are not clear cut, but observation of their use by
native speakers will help.
A few adjectives have different meanings depending on their positions. The most
common is grande. This adjective can mean ‘big’ in either position but when it means
‘great’ it is normally found in front of the noun:
e.g. un gran hombre a great man
un hombre grande a big man
Note that grande is shortened to gran when it comes immediately before a singular
noun.
Other adjectives whose meaning varies according to their position are:
viejo un viejo amigo
a former friend
un amigo viejo
an old friend (i.e. advanced in years)
pobre un pobre hombre
a poor man (i.e. to be pitied)
un hombre pobre
a poor man (i.e. he has no money)
cierto en cierta ocasión
on a certain occasion (i.e. particular)
un hecho cierto
a certain fact (i.e. beyond doubt)
A few common adjectives behave like grande and lose their final vowel when used
before a masculine singular noun:
bueno un buen chico but una buena idea
malo un mal asunto but una mala idea
primero el primer libro but la primera vez
tercero el tercer capítulo but la tercera semana
alguno algún día but alguna vez
ninguno ningún dinero but de ninguna manera
Basic Spanish: A grammar and workbook 54