This paper focuses on the expression of duration in (European and Brazilian) Portuguese. English is used for comparative purposes, since many of the issues to be discussed have been intently studied for this language. The paper has two main, parallel, goals: (i) a description of the Portuguese subsystem of duration, with an identification of the main structures involved in the expression of this semantic value, and (ii) an attempt to distinguish several conceptually different – though closely related – temporal subdomains within the semantic area under study. This second goal has obviously implications for the grammatical description that go well beyond the analysis of Portuguese. Two distinctions will be explored in some detail: one between strict duration and durative temporal location, which is not assumed by all authors, and another between the duration of telic and atelic eventualities. Other (semantic and/or syntactic) subtypes of strict duration that will be discussed are: argumental vs. adjunct, continuous vs. discontinuous, time-anchored vs. non-time-anchored, and planned vs. non-planned duration.