Contrastive tense and aspect data

Foreword This report originated in a paper I was to write with Lauri Carlson on the semantics of tense and aspect, and which never became ready, since the formalization part could not be made good enough in the required schedule ((rst trimester of 1991). In the original paper, I tried to describe the data and propose a theory of my own. Now I decided to select only the description of the problems and the general philosophy of the treatment I was proposing at that time, and publish it as an INESC internal report. This text is thus simply a linguistic paper on the diierences between the English and Por-tuguese tense and aspect systems, conceived to explain the latter to non-Portuguese-speaking readers, and to show that the diierences may bring signiicant insight for the study of each language. As far as my own work is concerned, this is an historical paper, where the origins of my theory of aspectual classes can be found, with detailed justiication and examples. However, at the time of my writing this introductory note (October 1991), I already have a more sophisticated theory of aspectual classiication and a rather strong opinion on how the data presented here should be reformulated. Nevertheless, if the data are mainly correct, their presentation here, no matter how biased by an early view, should endure a longer life than ending in the wastebasket, I think. Not only the bare facts can be cited, but a comparison of diierent theories trying to explain these facts would be possible. I therefore hope to cite this report often from now on, if only to demonstrate how my new views are more adequate. A word of caution should be added: this paper does not intend to cover all diierences between English and Portuguese, just a few. It is also not very detailed on the similarities, since its purpose was to highlight problems for translation (or for modelling the same phenomenon with the same model in two diierent languages). Thus it is not to be read by the layman who wants to learn Portuguese. I would say it requires solid knowledge of the two languages, or that the reader is familiar with the tense and aspect literature and its problems.