No. "Simply" is trying to modify "words" which is a noun. Use "simple".
Student or Learner
Hello, thanks for answering.
I had this sentence as an exercise, to mark it as correct or incorrect: "Babies often speak using simply words and phrases". The teacher said that "simply" should be replaced with "simple". My question id the following: Could "simply" also be OK, like an adverb modifying "speak"?
"Simply" could be an adverb modifying the verb "using".
not a teacher
Babies don't speak.
'Children learning to talk use simple words and phrases.'