Is there any specific name for the bold portions of the following sentences, or for their structure?

It has been suggested that drinking water is good for your health.

It is unknown how long could this last.

  • Your two examples are in the form of extraposition constructions. In conversation you could probably refer to the bolded expressions as either the matrix clause or as the nucleus (of the matrix clause) and the other person would probably understand what you are talking about, imo. The unbolded expressions, which are subordinate clauses, can be referred to as the extraposed subject. Note that the extraposed subject is not the grammatical subject. In both of your examples, the grammatical subject is the dummy pronoun "it".
    – F.E.
    Feb 7, 2014 at 21:33
  • @F.E. Why not write that as an answer? Seems reasonable to me, and there are other questions mentioning extraposition on EL&U, although we don't have a tag just for that. Feb 7, 2014 at 21:42
  • @FeralOink Well, I'm procrastinating before getting my coffee and hadn't intended to write a "real" answer type of post. :)
    – F.E.
    Feb 7, 2014 at 21:49
  • @F.E. Okay, I understand how that can be! Feb 7, 2014 at 23:03

1 Answer 1


It has been suggested is a passive construction.

It is unknown is a clause having dummy it as its subject. The verb is copular is, and the complement is the predicative adjective unknown.

  • And the unbolded terms are a clause and a phrase that are the logical subjects of both sentences for which the dummy, it stands in.
    – bib
    Feb 7, 2014 at 19:59

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.