This includes all the words an individual can employ in writing.
Speaking vocabulary
This refers to all the words an individual can use in speech.
Lexicon also refers to a reference book containing an alphabetical list of words with
information about them and can also refer to the mental faculty or power of vocal
communication (McCarthy, 1990, as cited in Taylor, 1990). According to McCarthy (1990, as
cited in Taylor, 1990) the role that mental lexicon plays in speech perception and production is a
major topic in the field of psycholinguistics and neurolinguistics.