My aim in this brief overview of second language acquisition (SLA) theory and syllabus design is to compare four recent proposals for criteria for grading and sequencing the units of second language classroom activity. These are proposals for structural, lexical, skills, and task-based syllabuses. All four proposals show continuity with, and development from, similar earlier approaches. First, Ellis (1993, 1994, 1997) argues for a role for the structural syllabus, alongside a meaning-based syllabus. This grammatical approach to syllabus design has a long history in second language pedagogy (see Mackey, 1965; Richards & Rodgers, 1986) and is clearly the basis of many currently popular English courses, such as New Horizon (Asano, Shimomura & Makino, 1997), and language programs throughout Japan and elsewhere. Second, Willis (1990) describes a lexical approach to syllabus design, inspired largely by the work of the Birmingham corpus analysis project (see Sinclair, 1987, 1991; Sinclair & Renouf, 1988). This approach can be seen as a development of earlier work on lexical grading by Palmer (1917), Thorndike (1921), West (1953, 1960) and Willis (1990, p. vi). For a discussion of the history of vocabulary control see Nation (1990). Third, Johnson (1996) proposes a skills syllabus building on his own earlier proposals for communicative syllabus design and those of others (Johnson, 1982; Munby, 1978; Wilkins, 1976: Yalden, 1983) within an expanded theoretical framework. Finally, the recent proposals for task-based syllabus design of Long (Long, 1985, 1997, in press; Long & Crookes, 1992), and Skehan (1996a, 1996b, 1998), while differing in scope and details, both develop themes apparent in earlier work by Brown (Brown, Anderson, Shillcock & Yule, 1984), Carroll (1980), and Prabhu (1987) amongst others.