Tense

Definition
Tense is traditionally defined as a grammatical feature or (deictic) category expressing a temporal relation between the event described by the verb and the moment of utterance.

Alternatively, tense can be defined as a grammatical feature or (deictic) category encoding a temporal relation between the topic time (Klein 1994) and an extra-linguistic reference point, the time of orientation (Huddleston & Pullum 2002).

Comment
Even though grammatical tense marking is found in the majority of the world's languages, there are also languages without grammaticalized tense (cf. Comrie 1985). Tense may either be marked by inflectional morphemes ('synthetic tense marking') or by free morphemes ('analytic tense marking').

Classification of temporal categories
A distinction can be made between (i) absolute tense, (ii) relative tense and (iii) absolute-relative tense (Comrie 1985).

The difference between absolute and relative tense is reflected in the use of time adverbials. Absolute time adverbials such as next year, four hours ago, in five days or tomorrow are related to the time of utterance. For example, tomorrow is the day after the day when the sentence is uttered. In contrast, relative time adverbials such as four hours before, five days after or on the day before require an inner-textual reference point.

Theories of tense
The description of the models of time reference developed by Reichenbach (1947), Comrie (1985) and Klein (1994) are represented in chronological order.

Reichenbach (1947)
According to Reichenbach, temporal reference involves three parameters: 'S' (point of speech), 'E' (point of event) and 'R' (point of reference). These parameters stand in a relationship of temporal precedence to each other (marked by ‘-‘), or they occur simultaneously (marked by ‘,’). For example, 'R-S,E' means that the point of speech (S) and the event (E) are simultaneous, whereas the point of reference (R) is located prior to the event and the moment of speech.

Three absolute tenses are distinguished, depending on the relationship between R and S (R=S: present, R-S: past, S-R: future). Aspect or relative tense is indicated by the relationship between E and R (E,R: simple, E-R: anterior, R-E: posterior). By combining the relation between R and S with the one between R and E, thirteen tenses can be distinguished. Two sets of three tenses can be subsumed under a single term, as natural languages do not normally seem to distinguish between them.

Comrie (1985)
Comrie (1985) adopts the parameters used by Reichenbach (E, S, R). However, unlike in Reichenbach's system the distinction between absolute tenses and relative tenses is reflected in his theory. Absolute tenses only indicate a relationship between E and S. The parameter 'R' is only relevant to the interpretatio of absolute-relative tenses.

E is related to S and (in the case of absolute-relative tenses) S to R in terms of the temporal relations 'simul', 'before' and 'after':

Klein (1994)
Like Reichenbach and Comrie, Klein uses three parameters: time of utterance (TU), time of situation (Tsit) and topic time (TT). The topic time takes up a central position in his theory. It is defined as "the time span to which the speaker’s claim on this occasion is confined" (Klein 1994: 4).

Tense is regarded as encoding a relationship between TT and TU. Three values are possible: incl (included in), after and before:

The three basic temporal categories are cross-classified with three aspectual categories, corresponding to the relationship between TSit and TT. There are four possibilities: incl ('included in', imperfective), at ('partly included', perfective), after (perfect) and before (prospective). Accordingly, twelve tense-aspect categories can be distinguished:

Links

 * Utrecht Lexicon of Linguistics