In linguistics, the aspect of a verb is a grammatical category that defines the temporal flow (or lack thereof) in a given action, event, or state. As its name suggests, the habitual aspect specifies an action as occurring habitually: the subject performs the action usually, ordinarily, or customarily. The habitual aspect is a type of imperfective aspect; the latter does not depict an event as a single entity viewed only as a whole, but instead specifies something about its internal temporal structure.
Dahl:p.101 found that the habitual past, the most common tense context for the habitual, occurred in only seven of 60 languages sampled, including English. he found :p.111 that the habitual can occur in combination with the predictive mood.
Habituality in English
Standard English has two habitual aspectual forms in the past tense. One is illustrated by the sentence "I used to go there frequently". The "used to [infinitive]" construction always refers to the habitual aspect when the infinitive is a non-stative verb; in contrast, when "used to" is used with a stative verb, the aspect can be interpreted as stative (that is, it indicates an ongoing, unchanging state, as in "I used to know that"), although Comrie:pp.98–99 classifies this too as habitual. "Used to ..." can be used without an indicator of temporal location in the past, or with a non-specific temporal indicator ("We used to do that", "We used to do that in 1974"); but Comrie:p.98–99 states that the time indicator cannot be too specific, so that "We used to do that every Monday in 1974" is not grammatical.
The second way that habituality is expressed in the past is by using the auxiliary verb "would", as in "Last summer we would go there every day." This usage requires a lexical indication of when the action occurred; by itself the sentence "We would go there every day" is meaningless, while "We used to go there every day" is meaningful even though it does not specify when. As with "used to", "would" also has other uses in English that do not indicate habituality: in "In January 1986 I knew I would graduate in four months", it indicates the future viewed from a past perspective; in "I would go if I felt better", it indicates the conditional mood.
English can also indicate habituality in a time-unspecific way, referring generically to the past, present, and future, by using the auxiliary "will" as in "He will make that mistake all the time, won't he?". As with "used to" and "would", the auxiliary "will" has other uses as well: as an indicator of future time ("The sun will rise tomorrow at 6:14"), and as a modal verb indicating volition ("At this moment I will not tolerate dissent").
Habitual aspect is frequently expressed in unmarked form in English, as in "I walked to work every day for ten years", "I walk to work every day", and "I will walk to work every day after I get well".:p.124
The Romance languages such as French, Spanish, Italian, and Portuguese do not have a grammatical form that is specific to the habitual aspect. In the past tense they do have a form called the "imperfect", which combines the past tense with the imperfective aspect; this form is used to indicate that a past ongoing process was either habitual or continuous.
- Bernard Comrie, 1976. Aspect. Cambridge University Press. Pp. 25, 30, 98-99, 114-115, 124.
- Östen Dahl, 1985. Tense and Aspect Systems. Blackwell. Pp. 95, 99-101, 111.