In an English textbook, I found the following sentence.

The Swiss tunnel took 17 years to build.

A tunnel is supposed to be built, so I think the sentence could be re-written.

The Swiss tunnel took 17 years to be built.

According to a native speaker, the first sentence is much better.

Should I use to build, to be built, or to have built in that sentence?


4 Answers 4


In your case , a) is indeed much better, because the tunnel itself took no part in the construction; it took [the tunnelling company, with their engineers and tunnelling machinery] 17 years to build it. A coral reef, on the other hand, might take some time to be built equally as well as some time to build.

  • Thank you for your comments. "It took [the tunnelling company...] to build it." is totally easy to understand, however due to my poor English skill, I cannot catch the meaning of "the tunnel itself took part in the construction." and "A coral reef..." (I sort of understand
    – othman
    Jun 19, 2017 at 6:25
  • (very sorry, I sent the comment on the way.) I sort of understand the meaning, but have little confidence.) A coral reef develops, on the other hand, a tunnel does not devlop...?
    – othman
    Jun 19, 2017 at 7:19

The first two suggested sentences are both grammatical and common. In this case, the meaning of the sentences is the same, but there are a couple of reasons to prefer 1.

First, sentence 1 is more concise. "To be built" adds extra verbiage without changing the meaning of the sentence.

Second, as Lambie points out, sentence 2 is passive. Passive sentences have a less immediate feel, and can give the impression of talking around the issue of who performed the action.

"The Swiss tunnel took 17 years to have built" is not a natural way to phrase this sentence.


to build and to be built have pretty much the same meaning.

The first sentence is an active sentence, while the second is a passive sentence.

So you can think of it like this:

In the first sentence, the people who are building the tunnel are in the focus, while in the second sentence you're putting the focus on the tunnel.

Both aren't wrong and both say essentially the same thing, but the second sentence is pointing out the tunnel more than the first.


It's quite difficult to substantiate: "According to a native speaker, "a." is much better," but in this case, the Ngram program, crude as it is, actually provides some useful material.

Both forms are possible (and both are grammatically correct). However, according to Ngrams "is built" is much the commoner of the two variants, so could be considered, if not "much better", at least the preferred one in printed texts:

enter image description here

  • Thank you for your comments. The title I posted is a little off the point. Actually, I thought the other alternative, "The Swiss tunnel took 17 years to have built." because the tunnel company had started to build it. However, since I would like to understand the difference between "to build" and "to be built" (in other word, ”verb transitive” or "verb intransitive" ?)
    – othman
    Jun 20, 2017 at 5:40
  • , I did not ask about "to have built".
    – othman
    Jun 20, 2017 at 6:33
  • 3
    These Ngrams are not the ones to use at all. Try 'years to build' and 'years to be built'. Oct 16, 2017 at 8:58

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