If I want to question someone about for how many hours a computer is turned on and running - and by the time of the question it is still running - which of the constructions below is more appropriate?

  1. For how long has your computer been running?

  2. For how long has your computer been run?

First of all, I'm not sure if construction number 1 is grammatically correct,
and secondly, in construction number 2 it seems the computer is not running anymore;
am I right?

4 Answers 4


Your first sentence uses a present perfect progressive active construction, while the second is a passive construction. Each has a different emphasis.

The second doesn’t necessarily mean that the computer is no longer running, but the first would in any case be more normal. You could make it sound less formal by writing For How long has your computer been running for?

If you know that the computer has stopped running, you could ask How long was your computer running for before it stopped?


There are two verbs run.
The first one is intransitive, and takes an agent subject.

  • Bill ran in the marathon last week.
  • Mary runs home every day for lunch.

That's the intransitive verb run that shows up in construction #1
(with the addendum that computers are considered agents, and what they do is run.)

How long has your computer been running?
which comes from
Your computer has been running for indefinite time.
via Wh-question formation,
using the perfect (has) and progressive (been) auxiliaries

Type 2 run is transitive -- because it's a causative -- and means 'cause to run'
type 1 run -- machine agents allowed -- in the downstairs clause,
and the causer and the runner are not the same agent.

  • He has run that horse every week.
  • He has run that chainsaw for an hour.
    (nb: He has would be pronounced He's in normal speech)

Like most transitive verbs, causatives can usually be passivized.

  • That horse has been run every week.
  • That chainsaw has been run for an hour.

By now you see where I'm going. Construction 2 has a type 2 run.

How long has your computer been run?
comes from
Indef has caused your computer to run for indefinite time
via Passive and Wh-question formation,
using the perfect (has) and passive (been) auxiliaries.

Takeaway: The difference between progressive be and passive be is that

  • Progressive be (am, is, are, was, were, be, been, being) comes before passive be,
    and it must be followed by a present participle (e.g, running)
  • Passive be comes after progressive be,
    and it must be followed by a past participle (e.g, run)

So they're both good and mean the same thing.
Just a passive causative, that's all.

  • So the complete passive construction would be: How long has your computer been run (by you)? Which sounds odd, and not very idiomatic. I have problems with "You run the computer", I think if "you" were an IT expert and were called to help run the computer then that I would understand. But if "you" is only a user, then the verb ought to be "use". The following passive construction would sound more natural: "How long has your computer been used?" The temptation to mentally tag ing onto "run" is overwhelming, I confess!
    – Mari-Lou A
    Nov 18, 2013 at 9:45
  • 1
    Probly. The 'run' metaphor works for any machine -- they are 'alive' enough to run (intransitively) by themselves, but also unalive enough for someone to run them (transitive). The transitive is, of course, the one that can be passivized. But since there's no reason for a transitive with an agent subject when the agency is Indef, the progressive intransitive is much commoner than the passive transitive in this context. Nov 18, 2013 at 14:53
  • I find the passive completely ungrammatical here. Computers aren't run, though software may be. “How long has this app been run/running?” is a case where both are fine (though I'd interpret them differently), but with computers, only #1 is possible for me. Jan 16, 2017 at 16:13
  • With modern microcomputers, sure. But up until about the 80s, computers were big hulking beasts that needed to be run by people in lab coats. Jan 16, 2017 at 16:17

If you're talking about an action that began in the past and is still happening, then you use the present perfect progressive/continuous tense (have/has been + participle). That makes your first sentence correct.

The preposition for is completely unnecessary. You simply could say:

How long has your computer been running?

If a preposition can be removed without changing the meaning, it can be omitted entirely. And while your phrasing is grammatically correct, a more modern phrasing would be:

How long has your computer been running for?

As you can see, for adds nothing to the question. It is superfluous.


My computer has been running for a long time. Now, it stopped to run. My computer is running now. Thus, it works even now.

  • 1
    Notwithstanding that this does not appear to answer the question asked, your sentence *It stopped to run is not a grammatical sentence in English, because for this sense stop takes an -ING verb following it, not a to-infinitive verb following it. “He stopped to ask directions” is very different from “He stopped asking directions”, and you have elected the wrong alternative here.
    – tchrist
    Jan 16, 2017 at 15:50

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