simply vs plainly

simply and plainly both are adverbs.

Word	Noun	Adjective	Verb	Adverb
simply	No	No	No	Yes
plainly	No	No	No	Yes

As adverbs, simply and plainly are synonyms defined as:

simply and plainly: in a simple manner; without extravagance or embellishment

simply (adverb)	plainly (adverb)
and nothing more	unmistakably (`plain' is often used informally for `plainly')
in a simple manner; without extravagance or embellishment	in a simple manner; without extravagance or embellishment
absolutely; altogether; really
(used for emphasis) absolutely