always vs forever

always and forever both are adverbs.

Word	Noun	Adjective	Verb	Adverb
always	No	No	No	Yes
forever	No	No	No	Yes

As adverbs, always and forever are synonyms defined as:

Other synonyms of always include constantly, incessantly, perpetually.

always (adverb)	forever (adverb)
at all times; all the time and on every occasion	for a limitless time
forever; throughout all time	for a very long or seemingly endless time
at any time or in any event	invariably
invariably
without variation or change, in every case