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Most word categories can express the duration of an event or situation
VARIETY OF CHOICE
The time taken by actions or events (often called “duration”) is one of those common meanings that English can express in numerous ways. Its importance means that language learners tend to encounter it quite early in their studies, but its variability means some possibilities remain unfamiliar until much later.
This post explores the variety of duration language. It is thus similar to other Guinlist posts about different ways of expressing a particular common meaning, such as examples, consequences, possibility and importance. As with those posts, the underlying belief is that familiarity with numerous alternative means of expression greatly assists paraphrasing (see 80. How to Paraphrase).
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RECOGNIZING DURATION
A problem with duration language is that much of it can also indicate when rather than how much time. Consider this:
(a) The premises are open between 10.00 and 16.00.
Without a context we cannot tell whether this is giving the length of opening hours or just their simple location in time: the sentence equally well answers both a “when” question and a “how long” one.
The discussion that follows is about language that can indicate duration, not language that only does so. Explanations of how duration is or is not indicated are offered occasionally, when considered necessary.
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DURATION INDICATORS
The idea of duration tends to be thought of as an adverb one (see 120. Six Things to Know about Adverbs, #1), yet it can actually be expressed with words and phrases in all of the main word classes (parts of speech). Some expressions indicate an exact length of time, others are vague.
1. Adverbs
Individual duration adverbs include all along, always, briefly, constantly, continuously, endlessly, eternally, ever, extensively, fleetingly, forever, instantaneously, long, perpetually, permanently, quickly, rapidly, (long) since, slowly, still, temporarily, throughout and not yet. The underlined words can express repetitive frequency as well as duration.
Exact duration is indicated by since (= “between then and now”) and by adverbs referring to the briefest possible time (e.g. instantaneously) or all possible time (e.g. all along, always, ever, throughout). For details of how to express duration with the words above, see the relevant section in 227. Time Adverbs.
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2. Prepositions
A few preposition phrases equate to an individual duration adverb like the ones above. For example, without end, in perpetuity and since then closely resemble endlessly, perpetually and since (see 85. Preposition Phrases and Corresponding Adverbs).
Perhaps the most familiar duration-showing prepositions are for, since and until (or till: see 132. Tricky Word Contrasts 4, #5). For accompanies explicit period lengths, since period beginnings and until period ends. For and until can express a duration occurring at any time, but since typically expresses one ending in the present (see 61. “Since” versus “Because”). When until expresses a duration ending in the present (e.g. until now, until today), it cannot imply future continuation. This meaning must be expressed with so far, up to now or to this day (see 48. Tricky Word Contrasts 1, #1).
Durations ending in the present typically accompany a verb in the “present perfect” tense:
(b) Engines have used petrol since 1876 (or for…years or until now).
A common error with for and since is adding so far or similar. This is unnecessary because the meaning is already present in both the preposition and the verb tense. However, adding until now (to indicate “not longer”) is acceptable.
With durations that are wholly in the past or future, since is rare. A common alternative is from (see 282. Features of History Writing, #9) combined, if the end of the duration is not obvious, with a later to, up to, until or American through. A different alternative is between… and… (not *between… to… – see 165. Confusions of Similar Structures 2, #4). Note, though, that between… and… has an alternative use of vaguely indicating a single moment within a time period instead of a duration throughout it.
Although for, since, from and until are especially useful for indicating an exact duration, for can also indicate inexact ones. It may accompany a vague number expression, like several months or billions of years (with -s of after billion-: see 67. Numbers in Spoken English, #3), or no number word at all. The following examples are all from the Guinlist post 164. Fixed Preposition Phrases:
for ages
for a (long/short) time
for a (brief) moment
for a time
for a (good) while
for good
for hours/days/weeks etc.
for life
for now
for the moment
for the time being
The underlined phrases here often need lasting instead of for when describing a preceding noun (e.g. illness lasting ages, employment lasting weeks). Note that for can be dropped before any kind of number word, but not always in expressions without one.
One other duration preposition – in – both indicates a length of time and says it is the total time needed to complete something:
(c) A book can be written in six months.
Using for here would leave the total duration of book writing unclear. Note the absence of -s’ time in (c), which indicates not duration but a future moment (see 293. Tricky Grammar Contrasts 4, #1). Other examples allowing in include CONDUCT A SURVEY, BUILD A HOUSE and CROSS THE OCEAN. Within is used similarly but means “in less than”.
Finally, there are throughout and right through instead of for + entire + time period. For example, working throughout the day means working for the entire day. During does not express this meaning, but rather indicates only some of a period (time location rather than duration). Similar to throughout is all in expressions like all along, all day, all year, all the time and all the while (see 169. “All”, “Each” and “Every”, “Specialised Use 2”).
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3. Conjunctions
The value of indicating duration with a conjunction rather than adverb or preposition is that it enables verb use in the duration (see 174. Eight Things to Know about Conjunctions, #1). Two prepositions that can become conjunctions with a subject + verb after them are since and until.
However, there is no obvious conjunction that can, like for, indicate duration without a clear start or end point. Although as, when and while can introduce extended time periods, these usually indicate when rather than how long (see 225. Simultaneous Occurrence). As long as is perhaps the nearest possibility:
(d) Plants grow as long as conditions are right.
The problem with as long as is that it usually implies a condition as much as a duration (see 230. Multi-Word Conjunctions), often equating to provided (that):
(e) Postal voting is possible as long as identification is provided.
One way to indicate duration more clearly in a conjunction-like way is by using an expression that is not strictly a conjunction but behaves like one. My best suggestion is all the time (when). Replacing as long as in (d) with this clearly indicates duration.
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4. Connectors
Connectors help two related ideas to be expressed in two sentences rather than one (see 40. Conjunctions versus Connectors). Possibilities for expressing duration include all this time, all along and the whole (of the) time (see 308. Complexities of “Whole”, last section).
However, these will not always be appropriate, and it is common instead to start a new sentence with what I call a connector synonym – something like This lasted… or It took…for this…, where a noun or pronoun like this (representing the previously-mentioned event or situation) links with one of the duration verbs suggested below.
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5. Verbs
Some verbs combine with a time expression (again without the word time) to express duration. With CARRY ON, CONTINUE, ENDURE, KEEP ON, LAST, PERSIST and PREVAIL, the time expression acts like an adverb, e.g. lasted (for) six years. With NEED, SPEND and TAKE, it is an object (…took a while); with PASS it may be a subject or object. The object of NEED and TAKE allows a following to verb, that of PASS and SPEND an -ing one.
Using a verb of duration (work lasted 10 hours) instead of an adverb phrase (worked for 10 hours) perhaps more clearly makes the duration the main sentence focus.
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6. Adjectives
All of the -ly adverbs listed above can drop their ending to become adjectives (e.g. a permanent problem). Two other vague adjectives are short-lived and long-lasting.
Exact duration can be indicated with a hyphenated combination of a number word and singular time noun, e.g. six-minute, two-day, five-year. These are not strictly adjectives but noun phrases used like adjectives (see 136. Types of Description by Nouns, #4). As a result, they cannot go by themselves after a noun and link verb like BE: they need either to accompany a…one (e.g. …was a five-hour one) or to drop the hyphen and use the plural of the noun (e.g. …was six minutes).
Note that when the number word before a time noun and other noun is a(n), the time noun needs the possessive form: an hour’s delay, a moment’s hesitation, a week’s work (see 58. Optional Apostrophe Endings).
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7. Nouns
Although there are nouns involved in some of the uses above (e.g. after prepositions and the verb TAKE), they cannot be considered noun indicators of duration. This is because their meaning – a particular length of time – is only part of the idea of duration. The other part – shown by words like for, until and TAKE – is the idea of actually passing through that time.
Common nouns indicating passage through time include a duration, a delay, a hesitation, a life, a period and a wait. They can express duration with an adjective like long or short, or a time noun, e.g. a duration of a month; a month-long duration; a month’s duration; a six-month duration. Typical verbs with these are HAVE, BE and There + BE:
(f) There was a month’s wait for materials.
(g) The life/duration of the project was two years.
The underlined words in (g) are replaceable by both delay to and time taken by. Both (f) and (g) resemble property-naming sentences (see 163. Ways of Naming Properties).
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PRACTICE EXERCISE: DURATION
To assist revision and memorization of points above, try paraphrasing each sentence below with the given word (suggested answers follow).
1. World War 2 lasted almost 6 years.
DURATION
2. High speed trains take less than a day to cross the continent
WILL CROSS
3. It is necessary to study for six years to become a doctor.
SIX-YEAR
4. Side effects of most drugs are short-lived.
LAST
5. The 20th century experienced unbroken technological development.
OCCURRED
6. Food needs have always been met successfully so far.
CONTINUOUS…NOW
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Suggested Answers
1. The duration of WW2 was almost 6 years.
2. High speed trains cross the continent within a day.
3. Six-year study is necessary to become a doctor.
4. Side effects of most drugs last briefly/a short time.
5. Technological development occurred throughout the 20th century.
6. Food needs have been met with continuous success up to (not until) now.