rickharrison.comArtificial Language Lab

from the 24th edition of Journal of Planned Languages
copyright © 1996-2006 by Richard K. Harrison

Verb Aspect

Rick Harrison

Verbs exhibit various changes in human languages; some tongues inflect their verbs to indicate tense (past, present, future); some inflect verbs to indicate the person and number of the subject and/or object; and some have special forms to indicate “moods” such as commands (imperatives), conditional or hypothetical statements, and so forth. An element of verb mechanics that seems to be neglected by many language designers is aspect.

(If you are not interested in invented languages but rather came here hoping to understand aspect in natural languages, read on! You will see that constructed languages provide some of the clearest examples of certain aspects.)

Aspect refers to the internal temporal constituency of an event, or the manner in which a verb’s action is distributed through the time-space continuum. Tense, on the other hand, points out the location of an event in the continuum of events.

Be advised that many of the verb forms which are traditionally called “tenses” in grammar books and foreign language text-books are actually aspects; the traditional terminology is misleading. The distinctions between she read that book, she used to read such books, and she was reading that book when I entered the room are aspectual distinctions rather than differences of tense.

Also be aware that there is no widespread agreement on terminology with regard to aspect. Among linguists, different people use the same terms in different ways; for example, the aspect which is properly called “perfect” is often called “perfective,” and this can lead to confusion when discussing languages that mark both a perfective-imperfective and a perfect-nonperfect opposition.

Not all languages have inflections or special words to mark aspect, but most languages have ways to express the meanings which are embedded in the aspectual categories. (Bulgarian has a very rich set of aspectual inflections, but some dialects of German have very few.) When explicit inflections or particles are not available to indicate aspect, languages will use less elegant methods, often involving idiomatic set phrases, such as “used to” which marks the past tense form of the habitual aspect in English. In many natural languages, we find verb forms that combine both aspect and tense, e.g. the Spanish imperfect Juan leía, “Juan was reading, Juan used to read,” which combines the past tense and imperfective aspect.

perfective and imperfective

In the sentence she was singing when I entered, the verb “entered” presents its action as a single event with its beginning, middle, and end included; this is an example of the perfective aspect. The verb “was singing,” on the other hand, refers to an internal portion of her singing, without any reference to the beginning or end of her singing; this is an example of imperfective aspect. In other words, the perfective treats a situation as a single shapeless whole, similar to the concept of a “point” in geometry, while the imperfective looks at the situation from the inside out and admits the possibility that the situation has a temporal shape. “Situation” refers to anything that can be expressed by a verb: a “state” (a static situation that will remain the same unless something changes it), an “event” (a dynamic situation considered as a complete, single item) or a “process” (a series of dynamic transactions viewed in progress).

A few examples, provided by Comrie1, might help us to clarify the perfective-imperfective distinction. “In French the difference between il régna (Past Definite) trente ans and il régnait (Imperfect) trente ans ‘he reigned for thirty years’ is not one of objective or subjective difference in the period of the reign; rather the former gathers the whole period of thirty years into a single complete whole, corresponding roughly to the English ‘he had a reign of thirty years,’ i.e. one single reign, while the second says rather that at any point during those thirty years he was indeed reigning... Similarly in Ancient Greek, we find the Aorist (perfective past) in ebasíleuse déka éte ‘he reigned ten years,’ or rather ‘he had a reign of ten years,’ to bring out the difference between this form and the Imperfect (imperfective past) ebasíleue déka éte ‘he reigned for ten years,’ or more explicitly ‘he was reigning during ten years.’”

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.

aspects that mark the duration
and stages of a situation

“Let’s start at the beginning.” Some languages can indicate the beginning of a situation with markers for an aspect called inceptive (also known as ingressive, commencative, initiative, etc.). For example, if a language has a verb that means “to be located inside something,”2 the inceptive aspect form of that verb would mean “to enter, to go into, to begin to be located inside something.” Having an affix to mark the purely inceptive aspect3 would enable a language to derive many common verbs from a small number of roots. For example, “to know” plus the inceptive aspect marker means roughly the same thing as “learn, discover, begin to know,” and “to have” plus the inceptive marker means “to acquire, to begin to have.” Many of the most frequently used verbs in English are merely inceptive variants of other common verbs.

The inchoative aspect indicates the beginning of a state (as opposed to a process or activity). Keep in mind that many of the conditions which are expressed by the copula and an adjective in English, such as “to be blue” or “to be large,” are expressed by stative verbs in some other languages. The inchoative aspect of “to be blue” means “become blue, turn blue,” and the inchoative form of “to be large” would mean “become large, get big.” Esperanto marks the inchoative with -ig^-, as in li bluig^is, ‘he turned blue.’ (Unfortunately this Esperanto affix also has some other meanings; it is not semantically pure.)

The counterpart of the inceptive is the cessative (also called cessive, egressive or terminative), which indicates that a situation is ending. The cessative form of “to be located inside” would mean “to go out of, to no longer be located within,” and the cessative form of “to have” would mean “to lose, to cease having.”

Some students of the Slavic languages believe there is an aspect that means “being at or near the middle-point of a process;” this corresponds to the English set phrase “right in the middle of...” as in I was right in the middle of taking a bath when the telephone rang. I have seen this aspect called “transkursive Aktionsart” in German publications, but I do not know its English name. “Transcursive” does not seem very accurate.

The artificial language Lojban has two aspects pertaining to activities that are temporarily suspended: the pausative (indicated by de’a) and the resumptive (marked by di’a). Examples:4 mi pu de’a citka le mi sanmi, ‘I stopped eating my meal for a while; there was a pause in my eating of my meal’; mi pu di’a citka le mi sanmi, ‘I resumed eating my meal; I went back to eating my meal.’

Some languages mark a punctual aspect; this indicates situations that are instantaneous, i.e. they do not have any duration5. In Russian there are many verbs marked with the suffix -nu which are inherently punctual, e.g. kashljanut’ ‘cough,’ blesnut’ ‘flash.’

Some linguists say there is a durative aspect indicating that a situation occupies a specified amount of time. Comrie gives the Russian example ja postojal tam chas ‘I stood there for an hour.’

The delimitative aspect indicates that the situation lasts for a brief period. Sentences such as let’s take a little walk and he talked a bit about the war contain this aspect, although English lacks an affix or inflection to mark it and therefore must use vague phrases which could also have other meanings.

The perdurative indicates that a situation lasts for a long period, perhaps longer than expected, for example conflict between Esperantists and Idists rages on and on. It is possible to make a distinction between the perdurative and a protractive aspect which means “for a much longer period of time than is normally implied by the root verb, perhaps indefinitely.” By having a marker for this aspect, a language can convert the verb “to have” into a verb that means “to keep, to retain, to go on having,” and the verb “to be located at” can be converted to a verb that means “to remain, to stay, to linger at.”

Lojban uses za’o to mark another aspect which Lojbanists call superfective; this identifies an activity that continues beyond its natural ending point, e.g. le xirma pu za’o jivna bajra, literally ‘the horse [past tense] [superfective aspect] compete-type-of run,’ loosely ‘the horse kept on running the race after the race was over.’

The iterative aspect indicates that an action is done repeatedly, many times, over and over again. (Esperanto’s -ad- sometimes has this meaning, as in pafado and frapadi.) Some linguists call the iterative “frequentative,” while others distinguish the frequentative from the iterative by saying that the frequentative indicates an action done often, with high frequency. To increase the usefulness of a marker for these aspects, an artificial language can add an affix that means “regularly, rhythmically, at predictable intervals” and another that means “intermittently, irregularly, at unpredictable intervals.”

The semelfactive aspect indicates that there is only one “stroke” of a normally iterative situation, e.g. a single knock at the door. The simulfactive indicates that a normally time-consuming or multi-stage situation is compressed, and occurs “all at once” or “in one fell swoop.”

mental aspects

The experiential aspect emphasizes the idea that a person has had the experience of doing something at least once prior to the time mentioned. There is more to the experiential aspect than the dry fact that something happened; the subject of an experiential verb is almost always a being which is capable of ‘having an experience.’ English doesn’t have a single distinct marker for this aspect, so we turn to Mandarin Chinese for examples; the experiential is marked by the suffix -guo in the neutral tone: ni chi-le yúchì méi-you ‘did you eat the shark’s fin?’ versus ni chi-guo yúchì méi-you ‘have you ever eaten (ever had the experience of eating) shark’s fin?’, likewise wo méi qù hen duo guójia ‘I did not visit many countries (during a certain trip or period of time)’ versus wo méi qùguo hen duo guójia ‘I haven’t visited (have never had the experience of visiting) many countries.’

Indicating that action is performed in an intentional manner might be classified as an aspect, although some might call it a modality. Adding the intentional aspect to the verb “to see” produces a word that means roughly the same thing as “to look at,” and adding the intentional to the concept “be aware of” produces the concept “pay attention to.”

The counterpart of the intentional is, of course, the unintentional or accidental. If we start with a verb that means “to hold something in one’s hand,” add the cessative marker to create a verb meaning “cease to hold,” and then add the unintentional marker, we now have a verb that roughly equals the English expression “to drop or let go of something (accidentally).” Similarly, if our artificial language has a verb meaning “to be in a sitting position,” we can add the inceptive aspect marker to create a verb meaning “to begin to sit,” and then we can add the unintentional aspect marker to create a word that corresponds to the English phrase “to (accidentally) fall on one’s butt, to fall on your arse.”

Tamil has an aspectual verb (vai, ve-) which indicates an aspect of future utility. Its meaning is something like “doing X for future use” or “considering the future consequences of the action.” Here are two examples:6 tanniirek kuticcu veppoom, ‘we will tank up on water, i.e. we will drink a lot of water now in order to avoid being thirsty in the near future’; pooliiskitte edeyaavadu olari vekkaadee ‘don’t go blabbing things to the police (because doing so might get you into even more trouble later).’

aspects indicating distribution

The distributive aspect indicates that an action occurs in a “one-after-another” manner. An example, from Russian: on zaper vse dveri ‘he locked all the doors’ (non-distributive) versus on pozapiral vse dveri ‘he locked all the doors individually, one by one.’

Alternation (doing X, then doing Y, then X, then Y and so forth – or two agents taking turns performing an action) could also be treated as a quasi-aspect in the design of a new language.

The generic aspect occurs in broad, general statements such as “squirrels live in trees.” Old Vorlin’s suffix -ur, which usually marked nouns that indicate a broad concept as opposed to a specific example of the concept, could also be used as a verb infix to mark the generic aspect: ful foburo hom, ‘birds (generally) fear humans.’ The generic aspect is called the “universal tense” in some language descriptions.

aspects of degree or intensity

The completive aspect indicates total completion of an activity, i.e. doing a process to the maximum possible degree. English examples: eat it all up (completive) versus eat (some of) it (non-completive); the fuel was used up versus the fuel was (perhaps only partly) used. The counterpart to this might be called the incompletive aspect; it indicates that the action was only partly completed or the verb’s object was partially affected.

The intensive, moderative, and attenuative aspects indicate the intensity of a situation. For example, when a liquid is moving in the moderative aspect, we use the verb “flow,” in the attenuative we say “trickle,” and in the intensive we use words like “gush” and “flood.” Similarly, when something emits light in the attenuative aspect we use verbs such as “glimmer” or “glow,” in the moderative we say “shine,” and in the intensive we say “glare.” An artificial language could derive these sets of closely related words from single roots using aspect markers, thus simplifying the task of learning the vocabulary.7

It is also possible to create an aspectual distinction for the concept expressed by the musical term crescendo, indicating an increase in intensity or degree; a few linguists have called this the evolutive aspect. Perhaps there is also an opposite decrescendo aspect.

Finally, an experimental suggestion: Marking the concept of “almost” or “just one step short of” with an aspectual affix would enable a language to convert “burn” to “smolder,” “believe” to “suspect,” etc.


If you want to design a language that is very expressive and able to derive a large number of related words from a relatively small inventory of roots, building a good system of aspect markers is essential. The ability to create these words by predictable derivation results in a vocabulary that has internally-defined meanings and is less vulnerable to misuse than an a posteriori lexicon taken from “recognizable” sources.



1 Bernard Comrie’s book Aspect (Cambridge University Press, 1976, ISBN 0-521-29045-7) gives a good introduction to aspect, and is the source of some of the examples used here.

2 Many of the relationships that are expressed by prepositions in English and its relatives are expressed by verbs in some other languages.

3 Esperanto’s prefix ek- indicates an aspect of commencement and/or brevity.

4 Drawn from material in the reference grammar (now at lojban.org).

5 Some observers will object that these very brief actions do occupy several milli-seconds, and their duration could be measured with the right equipment. That’s not the point; human languages express the perceptions of ordinary people, not of machines and technophiles.

6 From The role of metaphor in the grammaticalization of aspect in Tamil by Harold F. Schiffman.

7 Vorlin’s infixes -oz-, -ez-, and -ig-, indicate the intensive, moderative and attenuative aspects, respectively. These affixes can also indicate the density or concentration of a substance or thing, as in bomoza ‘having a dense tree population’ versus bomiza ‘having few trees.’


Update History

February 2001: added links to footnotes 6 and 7; corrected some typographical errors.

July 2001: Added a sentence to the generic aspect paragraph.

November 2006: Improved the typography and layout. Updated several links. Moved this page from rick.harrison.net to rickharrison.com. Added a paragraph to the introduction.


Regrettably some left-wing academics have objected to the humor in the paragraph about the prospective aspect. My objections to their objections are almost too numerous to list, but here is a sample :-) First of all, many rednecks call themselves rednecks, so the claim that it is a pejorative term is somewhat questionable. But if it is pejorative, so be it! I live and work among uneducated heterosexual white Christian rurally-accented folk in Florida. They are not shy about using pejorative terms to describe everyone on earth who is different from them in any way, shape or form; so, if I have tarred them with a pejorative term, I am merely an instrument of karma, which, as most of us know, is an unstoppable force.