Abstract: There is a debate concerning the history of demonstratives. Are they primitive or grammaticalized elements in languages? Moreover, notwithstanding the relevance of demonstratives to NP, nominals are not regarded as a potential source of grammaticalized demonstratives. The present study, based on synchronic observations, argues that the proximal demonstratives ða ‘this’ and ʔulaaʔ ‘these’, which constitute the nucleus of the demonstrative system of Standard Arabic, are grammaticalized elements. It also offers a new grammaticalization pathway and a new source of demonstratives. Arabic proximal demonstratives evolve from possessive adjectives, which are themselves grammaticalized from nominals that mean ‘oneself’ and ‘companion’. The motive underpinning this pathway is that the lexical sources and the grammaticalized elements share the property of being egocentric. Concerning medial and distal demonstratives, two further stages of grammaticalization occur: (1) the phonological derivation of two medial demonstratives from their corresponding proximal demonstratives and (2) the phonological derivation of two distal demonstratives from their corresponding medial demonstratives. The extended grammaticalization pathway is as follows: nominals that mean ‘self’ and ‘companion’ > possessive adjectives > proximal demonstratives > medial > distal. This pathway implies that the source of demonstratives may comprise more than one lexical word; however, they are meaningfully related, and their grammaticalization pathway towards forming the demonstrative system of Standard Arabic applies uniformly.