Verb: Perfective and Imperfective Aspect – Part 1
Verb: Perfective and Imperfective Aspect – Part 2
Verb: Perfective and Imperfective Aspect – Part 3

In addition to this, the Progressive in English has a number of other specific uses that do not seem to fit under the general definition of progres­siveness, for instance in I’ve only had six whiskies and already I‘m seeing pink elephants (Progressive of the stative verb to see, in the sense that I am only imagining things, in fact there are no pink elephants for me to see), or she’s always buying far more vegetables than they can possibly eat (where the function of the Progressive is simply to add a greater emotional effect than would be achieved by the straightforward she always buys far more vegetables than they can possibly eat). Finally, some uses seem to be purely idiosyncratic: thus while one can say either vow look well or you‘re looking well, with to seem, as opposed to to look, the Progressive is impossible, i.e. only you seem well, not *you’re seeming well; similarly with to sound in the appropriate sense: you sound hoarse, not *you’re sounding hoarse.

These examples demonstrate that in English the meaning of the Progres­sive has extended well beyond the original definition of progressiveness as the combination of continuous meaning and non-stativity. The question then arises whether the English Progressive should be given some specific defini­tion, i.e. whether the meaning of the English Progressive is so extended that we should not speak of a basic progressive meaning with various subsidiary meanings, but rather of some more general basic meaning which includes both progressive meaning and the various other meanings that the English Progressive has. For instance, one might suggest that the basic meaning of the English Progressive is to indicate a contingent situation: this would subsume progressive meaning itself, and also the use of the Progressive to indicate a temporary (contingent) state, and its use to indicate a contingent habitual situation.

This may well be the direction in which the English Pro­gressive is developing diachronically, but this does not give a completely adequate characterization of its function in the modern language. As noted in the above discussion, there are several idiosyncrasies in the use of the English Progressive that seem to militate against a general meaning being able to account for every single use of this form. Moreover, although many stative verbs can be used in the Progressive to indicate a contingent state, it is by no means the case that all stative verbs can be used in this way. For instance, the verb to know does not allow formation of a Progressive, even with reference to a contingent state (when she entered the room he knew/ *was knowing that she had brought some bad news), even with reference to a surprising state (fancy that! You know/*are knowing the speech act theo­ry!), even with reference to a counterfactual state (so you know/*are know-ing the speech act theory, do/are you?), even with reference to a changing degree of knowledge (I see I know/*am knowing more about the speech act theory with each day). Thus the extension of the English Progressive is more restricted than that of contingent state, although, as suggested above, it may well be that English is developing from a restricted use of the Progressive, always with progressive meaning, to this more extended meaning range, the present anomalies representing a midway stage between these two points.

Although the -ing form is an essential ingredient of the English Pro­gressive, in nonfinite constructions the -ing form (i.e. the Participle I and the Gerund) does not necessarily have progressive meaning; in fact, in such constructions it typically indicates only simultaneity (relative present time reference) with the situation of the main verb, as knowing that Tom was an expert, Jack turned to him for advice (i.e. as Jack knew, not *as Jack was knowing): anyone knowing more details is asked to contact the police (i.e. anyone who knows, not *anyone who is knowing): Greg s knowing quantum  mechanics amazed the teacher (i.e. the fact that Greg knew, not * the fact that Greg was knowing).

There is, however, one nonfinite construction where the -ing form does have specifically progressive force, namely after verbs of perception. Thus the difference between I saw the accused stab the victim and I saw the ac­cused stabbing the victim is one of aspect: stab is non-Progressive (in fact, it has perfective meaning, since the sense is that I witnessed the whole of the act of stabbing, and am not dividing the act up into separate beginning, middle and end, but presenting it as a single complete whole); stabbing is Progressive (it is not necessary for me to have witnessed the beginning and/ or end of the process, but only the middle, at least this is all I am alluding to). Similarly: I watched Fred surf the Net, where Fred’s surfing, no matter how long it lasted, is presented as a single complete situation, in contrast to I  watched Fred surfing the Net.