Irregular Forms

Some adjectives and adverbs have irregular comparative and superlative forms.  The most common are:

Adjective/Adverb		Comparative		Superlative
good bad great small well badly much little	bueno malo grande pequeño bien mal mucho poco	better worse greater less better worse more less	mejor peor mayor menor mejor peor más menos	the best the worst the greatest the least best worst most least	el mejor el peor el mayor el menor el mejor el peor el más el menos

Note that the bueno and malo change according to gender and number while grande and pequeño change according to gender.  The adverbs (the last four) do not agree with the noun.