Verb - Tense, Aspect, and Modality

Tense, Aspect, and Modality

Depending on the language, verbs may express grammatical tense, aspect, or modality. Grammatical tense is the use of auxiliary verbs or inflections to convey whether the action or state is before, simultaneous with, or after some reference point. The reference point could be the time of utterance, in which case the verb expresses absolute tense, or it could be a past, present, or future time of reference previously established in the sentence, in which case the verb expresses relative tense.

Aspect expresses how the action or state occurs through time. Important examples include:

• perfective aspect, in which the action is viewed in its entirety through completion (as in "I saw the car")
• imperfective aspect, in which the action is viewed as ongoing; in some languages a verb could express imperfective aspect more narrowly as:

• habitual aspect, in which the action occurs repeatedly (as in "I used to go there every day"), or
• continuous aspect, in which the action occurs without pause; continuous aspect can be further subdivided into

• stative aspect, in which the situation is a fixed, unevolving state (as in "I know French"), and
• progressive aspect, in which the situation continuously evolves (as in "I am running")

• perfect, which combines elements of both aspect and tense, and in which both a prior event and the state resulting from it are expressed (as in "I have studied well")

Aspect can either be lexical, in which case the aspect is embedded in the verb's meaning (as in "the sun shines", where "shines" is lexically stative); or it can be grammatically expressed, as in "I am running".

Modality expresses the speaker's attitude toward the action or state given by the verb, especially with regard to degree of necessity, obligation, or permission ("You must go", "You should go", "You may go"), determination or willingness ("I will do this no matter what"), degree of probability ("It must be raining by now", "It may be raining", "It might be raining"), or ability ("I can speak French"). All languages can express modality with adverbs, but some also use verbal forms as in the given examples. If the verbal expression of modality involves the use of an auxiliary verb, that auxiliary is called a modal verb. If the verbal expression of modality involves inflection, we have the special case of mood; moods include the indicative (as in "I am there"), the subjunctive (as in "I wish I were there"), and the imperative ("Be there!").