What creates an adjective when it is added to some nouns?

Some adjectives are formed by adding a suffix to a noun.

Some examples are:

angel + ic = angelic

acid + ic = acidic

child + ish = childish

accident + al = accidental

music + al = musical

danger + ous = dangerous

humor + ous = humorous

hope + ful = hopeful

use + ful = useful

hope + less = hopeless

use + less = useless

wonder + ful = wonderful

hate + ful = hateful

show + y = showy

wind + y = windy

Sometimes an ending vowel is dropped before adding the suffix, or an ending consonant is doubled before adding the suffix; for example:

fame - e + ous = famous

misery - y + able = miserable

volcano - o + ic = volcanic

industry - y + ial = industrial

bag + g + y = baggy

fun + n + y = funny

fur + r + y = furry

sun + n + y = sunny