As for languages in general, the lexicon of LIS comprises both signs that have developed naturally among native signers, and forms deriving from processes of borrowing from other languages, which enter the system as a consequence of contact among different languages. Signs developed naturally, showing a regular phonological pattern and used by all the members of the community define the native lexicon, whereas signs deriving from the contact with other languages constitute the non-native lexicon, which will be explored in LEXICON 2.
The present chapter deals with LIS native lexicon, exploring the main properties defining the signs belonging to this category. In the previous chapters, we have seen that signs result from the combination of specific phonological parameters, which constitute their sublexical structure (PHONOLOGY 1). As in all languages, within the native lexicon we find signs which constitute the established lexicon in that they are manifestation of lexemes, and signs resulting from visually-motivated constructions or processes of lexicalisation. We refer to these two groups as core (LEXICON 1.1) and non-core lexicon (LEXICON 1.2) respectively. Often, these two groups overlap and undergo the same processes of lexicalisation and standardisation, but also of modification. The following sections will explore the signs belonging to the core and non-core lexicon of LIS.