ABSTRACT
Human languages—both spoken and signed—comprise two distinct elements: vocabulary and grammar. Vocabulary comprises a list of symbols and their meanings. Grammar comprises the rules for either extending symbols or for combining them into more complex structures such as phrases and sentences. The essence of true language is that the combination of a finite number of symbols with a relatively small list of grammatical rules provides the means to create an infinite supply of sentences. The role of language in the left hemisphere extends far beyond the ability to communicate. Language is the significant feature of the L-mind, and both reveals and explains many of the differences which we will find between the operation of the individual hemispheres found in split-brain patients. Language in its fullest sense can only be said to exist when there is the ability to recognise and apply the grammatical rules of the language: the ability to recognise or use vocabulary falls well short of linguistic ability.
