as well as vs both

as well as

conj
  • And, in addition. 

  • Used other than figuratively or idiomatically: see as, well. 

prep
  • In addition to; further to. 

both

conj
  • Including both of (used with and). 

pron
  • Each of the two, or of the two kinds. 

det
  • Each of the two; one and the other; referring to two individuals or items. 

How often have the words as well as and both occurred in a corpus of books? (source: Google Ngram Viewer )