alone vs lonely

alone and lonely both are adjectives.

Word	Noun	Adjective	Verb	Adverb
alone	No	Yes	No	Yes
lonely	No	Yes	No	No

As adjectives, alone and lonely are synonyms defined as:

Other synonyms of alone include lone, solitary.

alone (adjective)	lonely (adjective)
exclusive of anyone or anything else	marked by dejection from being alone
radically distinctive and without equal	lacking companions or companionship
lacking companions or companionship	devoid of creatures
isolated from others	characterized by or preferring solitude

alone (adverb)	lonely (adverb)
without any others being included or involved
without anybody else or anything else