Tense and Aspect

With the exception of statements in textbooks in mathematics, almost everything that is expressed in natural languages involves time in some way. It is not easy to specify exactly what within the general realm of temporal reference should be subsumed under the headings tense and aspect, particularly because these terms have been used in widely divergent ways by different scholars in linguistics, logic and philosophy. Consider a declarative sentence such as (1) The water was cold. In its most common use, such a sentence "refers" to a definite time (point or period), although this time is not explicitly identified in the sentence itself. In English, the form of the verb tells us that the time is in the past -- that is, prior to the time at which the sentence is uttered. Otherwise, one would have said (2) The water is cold. But in a language such as Mandarin Chinese, the sentence (3) translates as both (1) and (2). Still, (3) shares with the English translations the property that it normally refers to a specific time when used. This kind of implicit time reference, then, is a universal property of human languages, which is independent of whether there is grammatical tense marking or not. Another universal property is the fundamentally deictic character of time reference -- most spoken sentences refer to the time of speech, and even in those that do not, time reference usually takes the time of speech as the point of departure, one consequence being that the truth-value of a typical sentence in a natural language depends on when it is uttered. The study of tense in formal semantics focuses on these and similar phenomena, which are at least analytically distinct from the notion of grammatical tense -- that is, the signaling of time reference by grammatical means such as verb inflection and auxiliaries. The tense operators of tense logic ("it has been the case that p", "it will be the case that p") as developed by Arthur Prior (Prior 1967) and reflected for example in Montague Grammar (Montague 1971) have only a partial overlap semantically and syntactically with the grammatical tenses of natural languages -- they cannot for instance account for the implicit reference to a definite point in time characteristic of examples such as (1) or for the agreement-like character of the informationally redundant tense marker in a sentence such as (4) It rained yesterday.

The field of aspect displays a similar duality in that it may alternatively be seen as the ontology of those entities that are most intimately connected with time, such as events, processes, states, properties, and so on, or as the study of the grammatical phenomena that relate to such types of entities and their manifestation in time. With respect to the ontology of temporal entities, which is sometimes subsumed under labels such as actionality or aktionsart, the most well known taxonomy is that of Vendler (1967). Vendler distinguishes states (as exemplified by "love somebody"), activities ("run", "push a cart"), accomplishments ("draw a circle"), and achievements ("win a race"). These four categories may also be distinguished in terms of binary distinctions. States are opposed to the three others by lacking dynamicity. Activities are opposed to accomplishments and achievements by being atelic or unbounded -- that is, unlike the latter, they do not have a well-defined endpoint or result-state. The difference between accomplishments and achievements may be described in terms of a distinction durative:punctual.

In the grammatical tradition, tense and aspect are usually seen as grammatical categories pertaining to the verb. In actual grammatical systems, temporal and aspectual properties are commonly interwoven in the same forms, and many linguists nowadays talk of tense-aspect systems as integrated wholes. Tense-aspect markings arise through grammaticization processes out of phrasal constructions usually involving lexical morphemes. Future markers may, for example, develop out of constructions involving motion verbs such as come and go. Advanced stages of grammaticization lead to the rise of inflectional markings by the fusion of earlier free morphemes with the stem of the head word. The high degree of grammaticization of inflectional tense-aspect markers is reflected in their obligatory character and tendency to be used even if informationally redundant (see (4)).

Grammatical tense-aspect markings tend to fall into a relatively small number of crosslinguistic types characterized by their SEMANTICS and typical way of expression. A subset of those types are regularly expressed inflectionally, by affixes or stem alternations (e.g., "strong verbs" in Germanic languages). The tense-aspect markings most frequently found in inflectional systems are imperfective, perfective, past, and future markings. The opposition between imperfective and perfective forms the core of a large part, maybe the majority, of all inflectional tense-aspect systems. Perfective verb forms prototypically express completed events in the past, as in Mandarin Chinese 'the snake died', where le is a perfective marker; imperfective forms prototypically express on-going activities or states that hold at the point of speech (but also habits), as in Modern Standard Arabic yaktubu rasa:'ilan 'he is writing a letter', where yaktubu is the imperfective form of the verb. The temporal reference properties may be overridden, however. Past markings may be applicable to all verb forms (as in English) or only to imperfective ones. Future markings are less often inflectional than the ones already discussed. Due to their special epistemological status, statements about the future tend to have modal nuances tinging the purely temporal character of grammatical futures.

Among tense-aspect markings that are usually expressed periphrastically (constructions involving more than one word) are progressives (a common diachronic source for imperfectives) as in English I am singing, and perfects (a common source for both pasts and perfectives), as in English I have sung. Progressives differ from imperfectives in having a narrower range of uses. The semantics of perfects is often described in terms of "current relevance" or in terms of an identity between "reference time" and "speech time" (in the terminology of Reichenbach 1947). Combinations of perfects and pasts yield pluperfects, used to express an event taking place before a reference time in the past.

Further types include habituals and generics, experientials (used to express that something took place at least once in the past), narratives (used to express that an event directly follows another in a narration), and markings of remoteness distinctions (e.g., hodiernal or "today" pasts versus hesternal or "yesterday" pasts).

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A note on mood, modality, tense and aspect affixes in turkish

-- Östen Dahl

References

Montague, R. (1971). Formal Philosophy, Richmond H. Thomason, Ed. New Haven, CT: Yale University Press.

Prior, A. (1967). Past, Present, and Future. Oxford: Clarendon Press.

Reichenbach, H. (1947). Elements of Symbolic Logic. New York: Collier-Macmillan.

Vendler, Z. (1967). Linguistics in Philosophy. Ithaca, NY: Cornell University Press.

Tense and Aspect

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