abruptly vs suddenly

abruptly and suddenly both are adverbs.

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

As adverbs, abruptly and suddenly are synonyms defined as:

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

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