The native lexicon refers to all signs that have arisen naturally within the language itself. Signs belonging to the native lexicon follow the phonological rules of the language they belong to. Moreover, for sign languages a further classification may be made depending on the phonological, morphological and semantic properties of the sign: the core lexicon and the non-core lexicon. The core lexicon is also known as the established or frozen lexicon. Signs belonging to this classification have a stable meaning and can be found in the basic vocabulary of the language. The non-core lexicon, instead, is known as the productive lexicon. Signs belonging to this category, like classifier constructions, do not have a stable meaning independently of the context. This chapter offers an overview of different types of lexical elements belonging to these two main categories.