yawning vs inattentive

yawning is a noun but inattentive is not a noun.

Word	Noun	Adjective	Verb	Adverb
yawning	Yes	Yes	No	No
inattentive	No	Yes	No	No

yawning (noun)	inattentive (noun)
an involuntary intake of breath through a wide open mouth; usually triggered by fatigue or boredom

yawning (adjective)	inattentive (adjective)
showing lack of attention or boredom	showing a lack of attention or care
gaping open as if threatening to engulf someone or something	not showing due care or attention
with the mouth wide open indicating boredom or sleepiness