suddenly vs abruptly

suddenly and abruptly both are adverbs.

Word	Noun	Adjective	Verb	Adverb
suddenly	No	No	No	Yes
abruptly	No	No	No	Yes

As adverbs, suddenly and abruptly are synonyms defined as:

Other synonyms of suddenly include all of a sudden, dead, of a sudden, on the spur of the moment, short.

suddenly (adverb)	abruptly (adverb)
quickly and without warning; happening unexpectedly; on impulse; without premeditation	quickly and without warning; happening unexpectedly; on impulse; without premeditation