Regarding the process of word formation, it can be stated that:
I. Playmate is an example of a compound word formed by combining the words “play” and “mate”.
II. Inflection occurs when a suffix is added to a word without changing its grammatical class as in becoming (...Pluto, was now becoming old...).
III. Derivation occurs when affixes are added to a word to change its meaning and, in some cases, its grammatical class.