In analyzing code-switching in spoken languages, Chan (2003, 2008) proposes that only functional heads with their associated language determine the order of the complement. In this paper, we examine whether Chan's analysis can account for code-blending in Hong Kong Sign Language (HKSL) and Cantonese by a deaf child (2;0.26–6;6.26) and three deaf adult native signers. HKSL and Cantonese differ in head directionality so far as the functional elements of modals, negators, and auxiliaries are concerned. They are head-final in HKSL but head-initial in Cantonese. The HKSL–Cantonese code-blending data in this study largely conform to Chan's analysis, where the order of the complement is determined by which language the functional head appears in. However, code-blending the functional heads of a similar category in both languages leads to either order of the complement. Also, the deaf child's apparent violations of adult HKSL grammar reveal crosslinguistic influence from Cantonese to HKSL during code-blending.
