This paper seeks to show that Activities do not form a natural class with neither Actions nor States. We suggest that these categories are not objective situation classes, but different (subjective) ways of conceptualizing the dynamics and the discreteness of a given situation. Having been a situation conceptualized as an Action, an Activity or a State (non-discrete o discrete), the discourse chunk which represents it is organized according to a particular mode or textual type which reflects the speaker perspective: a narrative, an exposition of activities, an exposition of states, or a description. Provided that Activities determine one particular way of organizing the discourse structure, it does not make sense to include them into neither of the other two classes. A comparison of English texts with Catalan texts contributes, in this paper, to make more obvious the need for an independent treatment of Activities.