Category: adjectives and adverbs...

adjectives have no inflections aside from the determiners
qualities can be broadly classified as abstract, comparative, or physical
when you want to give more information about something than you can give by using a noun alone, you can use an adjective to identify it or describe it in more detail
an adjective is used either before a noun or after a link verb and it is either qualitative (happy, intelligent) or classifying (financial intellectual)
adverbs describe the manner in which things are done: time, frequency, duration; place; manner/how/circumstances; degree; focusing; linking; negative
the top 20 most frequent adjectives, adverbs
the endings -er and -est denote degrees of comparison and are regarded as noninflectional suffixes (English is the only European language to employ uninflected adjectives)
adjectives and adverbs can function as nouns or verbs and adverbs can function as adjectives
The order in multiple attribution tends to be as follows: determiner, quantifier, adjective of quality; adjective of size, shape, or texture; adjective of color or material; noun adjunct (if any, head noun <that one solid, round, oak dining table>)
Adverbs are more mobile than adjectives.