Complex sentence: Systemic functional grammar (SFG) is a grammar model developed by Michael Halliday--the most well-known component of a broad social semiotic approach to language called systemic-functional linguistics, originally articulated by Halliday in the 1960s.
Split into simpler sentences: Systemic functional grammar (SFG) is a grammar model developed by Michael Halliday. It is the most well-known component of a broad social semiotic approach to language called systemic-functional linguistics, originally articulated by Michael A.K. Halliday in the 1960s.