中山大學 SUN YAT-SEN UNIVERSITY Halliday(2008: 189 口 Complementarities in language(《语言系统 的并协与互补》 a i am committed to working towards a coherent g account of language which is",,in the sense that it can be helpful to at least some of the large numbers of people who are in some E way or other engaging with language in the course of their work ∽cz,zcz◼ Halliday (2008: 189)  Complementarities in Language（《语言系统 的并协与互补》  I am committed to working towards a coherent account of language which is “appliable”, in the sense that it can be helpful to at least some of the large numbers of people who are in some way or other engaging with language in the course of their work