Halliday has been inspirational. Among his seminal linguistic concepts are the notions of language as social semiotics and language as action. The former refers to the idea that linguistic forms encode the world which socially constructed. As such linguistic studies include the issues of 1) text 2) context 3) register 4) code 5) lingual system and 6) social structure. The latter suggests the idea that linguistic theorization should be attempted in view of the world of praxis linguistics should be socially accountable. These two concepts central to Hallidayan linguistics in turn have been influential to development of critical linguistic theories and critical discourse analysis.