allowable vs allow

allowable is an adjective but allow is not an adjective.

Word	Noun	Adjective	Verb	Adverb
allowable	No	Yes	No	No
allow	No	No	Yes	No

allowable (adjective)	allow (adjective)
that may be permitted especially as according to rule
deserving to be allowed or considered
deductible according to the tax laws

allowable (verb)	allow (verb)
	allow or plan for a certain possibility; concede the truth or validity of something
	give or assign a resource to a particular person or cause
	consent to, give permission; permit
	allow the presence of or allow (an activity) without opposing or prohibiting
	let have
	grant as a discount or in exchange
	make it possible through a specific action or lack of action for something to happen
	allow the other (baseball) team to score
	make a possibility or provide opportunity for; permit to be attainable or cause to remain
	afford possibility