Habitual and progressive

The imperfective aspect can be sub-divided into habitual and continuous aspects. The habitual aspect refers to a situation that is protracted over a long period of time, or a situation that occurs frequently during an extended period of time, to the point that the situation becomes the characteristic feature of the whole period. An example of the habitual aspect in the past tense is, the neighbor’s dog used to wake me up by barking every morning. A present-tense example would be I (usually) ride the bus home from work. We must be careful to avoid two common misconceptions about the habitual. First, the habitual is not the same thing as the iterative or frequentative aspect, which merely refers to something that happens several times without being the foremost characteristic of a period of time (e.g. he coughed over and over again, then recited his poem). Second, the past habitual does not necessarily imply that the condition is no longer true; it is perfectly reasonable to say Erik used to be a member of the Volapük League, and he still is.

The continuous aspect encompasses the progressive aspect. Progressivity is a special type of imperfectivity which emphasizes that an action is in progress; often this is mentioned to provide a background or frame of reference for some other situation. An example of the progressive aspect is English John is singing, Spanish Juan está cantando, Italian Gianni sta cantando, Icelandic Jon er að syngja, Irish tá Seán ag canadh.

Some behaviors of the progressive in English are relatively strange compared to other languages. One example of this is the use of the progressive to indicate a more temporary situation than is indicated by the basic form of the verb, e.g. the Sphinx stands by the Nile versus Mr. Smith is standing by the Nile, or I live at 123 Main Street (semi-permanently) versus I’m living at 123 Main Street (temporarily). English generally does not use progressive forms of verbs of passive perception; the phrase *you aren’t hearing seems odd in English, but the Portuguese counterpart você nao está ouvindo is perfectly acceptable. However, these verbs do take the progressive in English when referring to counterfactual perception, as in you aren’t hearing voices from beyond the grave again, are you? Also note that English environmental verbs, such as “to rain” and “to snow,” almost always occur in the progressive form when they are in the present tense, but some related languages (e.g. Icelandic) never use the progressive form of the corresponding verbs. If you are trying to design a neutral auxiliary language for international communication, you must be careful to exclude these anglo-centric, unpredictable uses of the progressive aspect from your design.

Perfect (retrospective) and prospective

Unlike most aspects, the perfect does not tell us anything about the internal temporal constituency of a situation. Instead, it indicates the continuing relevance of a past situation. In other words, the perfect expresses a relation between two points on the continuum of events. Linguists are not unanimous in classifying the perfect as an aspect rather than as a tense. An example of the perfect, from English: I have lost the book (perfect) versus I lost the book (non-perfect). The perfect can indicate a relation between a state in the past and an even earlier event, e.g. John had read the book; it can express a relation between a past event and the present state, e.g. John has read the book; and it can express a relation between a future state and an event that occurs prior to it, e.g. John will have read the book.

English often uses the perfect to express a situation that started in the past and continues into the present, e.g. we have lived here for a long time. Many other languages use the present tense in such sentences: French j’attends depuis trois jours, German ich warte schon drei Tage, Russian ja zhdu uzhe tri dnja ‘I have been waiting for three days.’

Because the term “perfect” is likely to be confused with “perfective,” and because its counterpart is called “prospective,” I would suggest that “retrospective” is a better name for this verb form.

The perfect verb form expresses a relation between a situation and some event that happened before it. In some languages we also find a prospective form which relates a state to some event that happens after it. In English the prospective is indicated by phrases such as “to be about to” and “to be on the point of,” as in John is about to resign from his job. In the “redneck” dialect of American English, the prospective is marked by the phrase “fixin’ to,” e.g. I was fixin’ to drive to work when I noticed a tornado comin’ toward the trailer park.