Yes, it is. It is the comparative form of the adjective smart (meaning more intelligent, not more fashionable).
Yes, there has been at least one girl who was smarter than at least one boy.
Cautious IS an adjective. An adjective is an action!
The word "it" is not an adjective (it is a pronoun). A word is an adjective if it modifies (defines, characterizes) a noun or pronoun. The big tent - big is an adjective He is tall - tall is an adjective This key - this (while arguably called a determiner) is a demonstrative adjective
probable is an adjective
Stable is an adjective.
It can be an adverb (much smarter, much more easily), but it can also be an adjective (e.g. much has been said),
smarter
The coyote is smarter
Dumber is the opposite of smarter.
A raven seems to be smarter.
they get smarter bye watch the others
The superlative of smarter is "smartest."
They are smart, but humans are smarter.
Yes it does make you smarter
Smarter (in the sense of cleverer) = Acutulior
No I am smarter than every body.
noni is smarter than david