中山大學 SUN YAT-SEN UNIVERSITY Lexis and grammar In SFl, language is seen as a complex 2=∽zcz<z∽K semiotic system, having various levels or strata: semantics, lexicogrammar and phonology/phonetics (Halliday 2004a: 24)3 0zcz=<:Lexis and grammar ◼ In SFL, language is seen as a complex semiotic system, having various levels or strata: semantics, lexicogrammar and phonology/phonetics. (Halliday 2004a: 24)