中山大學 SUN YAT-SEN UNIVERSITY Complementarities in language include those between 口 lexis and grammar a language as system and language as text zcz< a two modes of speaking and writing a Halliday(2008: 1): The complementarities in language are highlighted here with the aim of achieving a coherent account of language 1∽zcz<∽ which is‘ appliable”◼ Complementarities in language include those between:  lexis and grammar  language as system and language as text  two modes of speaking and writing  Halliday (2008: ii)：The complementarities in language are highlighted here with the aim of achieving a coherent account of language which is “appliable