This thesis analyses tense and aspect, in particular the Aspect Hypothesis (Salaberry & Shirai 2002; Bardovi-Harlig 2000; Andersen & Shirai 1996) and introduces an approach to teaching it: sociocognitive metaphorm (SCM). Sociocognitive is a combination of sociocultural theory (Lantolf & Appel 1996; Lantolf 2000) and cognitive grammar (Langacker 1987,1991). These theories are compatible because they share the psycholinguistic position that language and language development are conceptually based. Metaphorm is a combination of metaphor and form. Metaphor is central to concept development (i.e., conceptual metaphor). Form refers to grammatical structure. Much of temporal relations are expressed metaphorica1ly and hence metaphor also plays an essential role in the tense-aspect conceptualisation, grammaticalisation and acquisition process. The thesis is divided into four parts: Developing SCM, SCM Theory, Researching SCM and Applying SCM. Developing SCM contains a second language acquisition analysis of the Aspect Hypothesis as well as a diachronic and synchronic grammatical meta-analysis of aspect. SCM Theory outlines the process of integrating cognitive grammar with sociocultural theory. Vygotskian (1978, 1986) approaches to learning development, in particular, the zone of proximal development (ZPD), playa prominent role in this part. Researching SCM presents quantitative and qualitative results from a holistic (i.e., metaphoric) empirical classroom study designed to illuminate teaching tense-aspect as sociocognitive metaphorm as well as results from a more analytical (i.e., metonymic) follow-up study investigating the sequence and rate of acquisition of perfect aspect and future tense. The holistic study was longitudinal involving eleven different taskplans to teach grammar through metaphor. The follow-up research study analyses a sequence of instruction based upon conceptualisation processes. The tmal part, Applying SCM, to illustrate the sociocognitive pedagogical approach to teaching grammar as metaphor, includes revised taskplans that were utilised in the empirical research part of this study. The thesis concludes with a summary of the conceptual nature of tense-aspect as well as suggestions for teaching it.