perceptive vs observing

perceptive and observing both are adjectives.

Word	Noun	Adjective	Verb	Adverb
perceptive	No	Yes	No	No
observing	No	Yes	No	No

perceptive (adjective)	observing (adjective)
having the ability to perceive or understand; keen in discernment	quick to notice; showing quick and keen perception
of or relating to perception