Grammatical tense

In grammar, tense is a category that expresses time reference. Tenses are usually manifested by the use of specific forms of verbs, particularly in their conjugation patterns.
The main tenses found in many languages include the past, present, and future. Some languages have only two distinct tenses, such as past and nonpast, or future and nonfuture, while some languages make finer tense distinctions, such as remote vs recent past, or near vs remote future. There are also tenseless languages, like most of the Chinese languages, however, these languages do refer to time in different ways.
Tenses generally express time relative to the moment of speaking. In some contexts, however, their meaning may be relativized to a point in the past or future which is established in the discourse. This is called relative tense. Some languages have different verb forms or constructions which manifest relative tense, such as pluperfect and "future-in-the-past".
Expressions of tense are often closely connected with expressions of the category of aspect; sometimes what are traditionally called tenses may in modern analysis be regarded as combinations of tense with aspect. Verbs are also often conjugated for mood, and since in many cases the three categories are not manifested separately, some languages may be described in terms of a combined tense–aspect–mood system.

Etymology

The English noun tense comes from Old French tens "time", from Latin tempus, "time". It is not related to the adjective tense, which comes from Latin tensus, the perfect passive participle of tendere, "stretch".

Uses of the term

In modern linguistic theory, tense is understood as a category that expresses time reference; namely one which, using grammatical means, places a state or action at a time relative to that of the utterance. Nonetheless, in many descriptions of languages, particularly in traditional European grammar, the term "tense" is applied to verb forms or constructions that express not merely position in time, but also additional properties of the state or action – particularly aspectual or modal properties.
The category of aspect expresses how a state or action relates to time – whether it is seen as a complete event, an ongoing or repeated situation, etc. Many languages make a distinction between perfective aspect and imperfective aspect ; the former may employ a perfect tense, but such a relationship between aspect and tense may not be simple. Some of the traditional "tenses" express time reference together with aspectual information. In Latin and French, for example, the imperfect denotes past time in combination with imperfective aspect, while other verb forms are used for past time reference with perfective aspect.
The category of mood is used to express modality, which includes such properties as uncertainty, evidentiality, and obligation. Commonly encountered moods include the indicative, subjunctive, and conditional. Mood can be bound up with tense, aspect, or both, in particular verb forms. Hence, certain languages are sometimes analysed as having a single tense–aspect–mood system, without separate manifestation of the three categories.
The term tense, then, particularly in less formal contexts, is sometimes used to denote any combination of tense proper, aspect, and mood. As regards English, there are many verb forms and constructions which combine time reference with continuous and/or perfect aspect, and with indicative, subjunctive or conditional mood.
Particular tense forms need not always carry their basic time-referential meaning in every case. For instance, the historical present is a use of the present tense to refer to past events. The phenomenon of fake tense is common crosslinguistically as a means of marking counterfactuality in conditionals and wishes.

Possible tenses

Not all languages have tense: tenseless languages include Chinese and Dyirbal. Some languages have all three basic tenses, while others have only two: some have past and nonpast tenses, the latter covering both present and future times, as in Arabic, Japanese, and English; whereas others such as Greenlandic, Quechua, and Nivkh have future and nonfuture. Some languages have four or more tenses, making finer distinctions either in the past or in the future. The six-tense language Kalaw Lagaw Ya of Australia has the remote past, the recent past, the today past, the present, the today/near future and the remote future. Some languages, like the Amazonian Cubeo language, have a historical past tense, used for events perceived as historical.
Tenses that refer specifically to "today" are called hodiernal tenses; these can be either past or future. Apart from Kalaw Lagaw Ya, another language with such tenses is Mwera, a Bantu language of Tanzania. It is also suggested that in 17th-century French, the passé composé served as a hodiernal past. Tenses that refer to the past before today or the future after today are called pre-hodiernal and post-hodiernal respectively. Some languages also have a crastinal tense, a future tense referring specifically to tomorrow ; or a hesternal tense, a past tense referring specifically to yesterday. A tense for after tomorrow is thus called post-crastinal, and one for before yesterday is called pre-hesternal.
Another tense found in some languages, including Swahili, is the persistive tense, used to indicate that a state or ongoing action still continues. The Washo language has tenses to indicate if an event occurred before the speaker's lifetime.
Some languages have special tense forms that are used to express relative tense. Tenses that refer to the past relative to some time other than that of the utterance are called anterior; these include the pluperfect and the future perfect. Similarly, posterior tenses refer to the future relative to the time under consideration, as with the English "future-in-the-past": he would go. Relative tenses are also sometimes analysed as aspects: the perfect aspect in the anterior case, or the prospective aspect in the posterior case.
Some languages, such as Nez Perce or Cavineña also have periodic tense markers that encode that the action occurs in a recurrent temporal period of the day or of the year.
Some languages have cyclic tense systems. This is a form of temporal marking where tense is given relative to a reference point or reference span. In Burarra, for example, events that occurred earlier on the day of speaking are marked with the same verb forms as events that happened in the far past, while events that happened yesterday are marked with the same forms as events in the present. This can be thought of as a system where events are marked as prior or contemporaneous to points of reference on a timeline.

Tense marking

Morphology of tense

Tense is normally indicated by the use of a particular verb form – either an inflected form of the main verb, or a multi-word construction, or both in combination. Inflection may involve the use of affixes, such as the -ed ending that marks the past tense of English regular verbs, but can also entail stem modifications, such as ablaut, as found as in the strong verbs in English and other Germanic languages, or reduplication. Multi-word tense constructions often involve auxiliary verbs or clitics. Examples which combine both types of tense marking include the French passé composé, which has an auxiliary verb together with the inflected past participle form of the lexical verb; and the Irish past tense, where the proclitic do appears with the affixed or ablaut-modified past tense form of the lexical verb.
Indications of tense are often bound up with indications of other verbal categories, such as aspect and mood. The conjugation patterns of verbs often also reflect agreement with categories pertaining to the subject, such as person, number and gender via portmanteau morphs. It is thus not always possible to identify elements that mark any specific category, such as tense, separately from the others.

Nominal tense

A few languages have been shown to mark tense information on nouns. This may be called nominal tense, or more broadly nominal TAM which includes nominal marking of aspect and mood as well.
For example, the Kayardild language uses case markers to mark tense:
The verb stays the same, with the modal cases being used to show tense in the sentences.

Tenseless language

A tenseless language is one that does not mark tense information at all. Examples are Burmese, Dyirbal, most varieties of Chinese, Malay, Thai, Yucatec Maya, Vietnamese, and in some analyses Greenlandic and Guaraní.
Tenseless languages can and do refer to time, but they do so using lexical items that establish time reference, or by using combinations of aspect, mood. For example, most Sinitic languages express time reference chiefly by lexical means – through adjuncts, time phrases, and so on. Time information is also sometimes conveyed as a secondary feature by markers of other categories, as with the aspect markers 了 le and 過 guò, which in most cases place an action in past time. However, much time information is conveyed implicitly by context – it is therefore not always necessary, when translating from a tensed to a tenseless language, say, to make explicit in the target language all of the information conveyed by the tenses in the source.
For example, in Mandarin, though the language is tenseless, the auxiliary verb 会 huì can be used to express an action that will occur in the future:

Syntax of tense

The syntactic properties of tense have been prominent in formal analyses of how tense-marking interacts with word order. Some languages allow an adverb between a tense-marked verb and its direct object ; in other words, they permit order. In contrast, other languages do not allow an adverb to come between a tense-marked lexical verb and its direct object, and instead require order.

	French	English
Tense-marked verb, then adverb	Jules apprend vite ses rôles.	*Jules learns quickly his lines.
Tense-marked verb, then adverb	Jules a vite appris son rôle.	Jules has quickly learnt his lines.
Adverb, then tense-marked verb	*Jules vite apprend ses rôles.	Jules quickly learns his lines.
Adverb, then tense-marked verb	*Jules vite a appris son rôle.	*Jules quickly has learnt his lines.

Tense in syntax is represented by the category label T, which is the head of a TP.