1.    A noun clause is formed with subordinator + subject + verb (+ rest of clause).  Noun clauses usually begin with words called subordinating conjunctions or subordinators.

Subordinators in noun clauses1

how how soon whenever who however if how long
where whoever how long (The fact) that wherever whom how many
whomever why how many what whatever which how much
whose how often when whichever whether (or not)

A noun clause can serve these functions in a sentence:


  • (2The fact) that secondhand smoke, like active smoking, can cause serious health problems has been shown by several studies.

  • That they refused the money showed their sense of pride.

  • How the 2010 Olympics will impact Vancouver’s homeless is a serious issue.

3Subject complement:

  • Their mistake was that he refused to take his friend’s advice.

  • The problem was that they lost all their money playing poker.

  • The question is whether or not the Canucks will continue to attract fans.

Adjective complement:

  • We are all afraid (that) the final exam will be difficult.

  • I'm sorry (that) I'm late.

  • I'm not sure whether we can still go.

Noun complement:

  • The news that they were expelled for plagiarism surprised us all.

Direct object:

  • In 1978 scientists discovered (that) the planet Pluto has a satellite.

  • The dealer promised (that) I would receive a $500 rebate.

Verbs that permit or require tensed that-complements as direct objects:

believe claim expect know assume discover explain
find find out imagine learn perceive prove see
point out promise show think understand


  • They didn't know how they should answer.
  • They asked them about whether they should go.

Object of a preposition:

  • How do you feel about the fact that SFU will close for two weeks during the Olympics?
  • Microeconomics is concerned with how wheat prices rise while cotton prices fall.
  • Scholars disagree over who really wrote some of Shakespeare’s sonnets.


2.    Some noun clauses can be reduced to infinitive phrases:

Noun clause:

  • They told me that I should drive.  (command)
  • They asked me if I would help. (request for action)
  • I'm not sure how I can help. (modal)
  • How society should distribute scarce goods is a central economic problem in any society.(question)

Infinitive phrase:

  • They told me to drive.
  • They asked me to help.
  • I’m not sure how to help.
  • How to distribute scarce goods is central economic problem in any society.

1 When a noun clause begins with that and is used as a direct object in a sentence, you can omit that, with nochange in meaning.  THAT does not have any function within a noun clause (unlike adjective clauses). It simply introduces it, and therefore, can be omitted.  WHETHER and IF also do not have any function within a noun clause, but because they carry important information, cannot be omitted: I wonder whether they (subject) bought (verb) an expensive car.  Other "WH-words" DO have a function within a noun clause, just as they do in adjective clauses, and, therefore, cannot be omitted ... even when they're not the subject.  I wonder who(m) (indirect object) they (subject) told. (verb)

2 The fact + that clauses are similar in meaning to that clauses; however, they are generally considered less formal.

3 The subject complement is the word or clause that follows a linking verb (copula, of which to be is the most common) and complements, or completes the subject of the sentence by either (1) renaming it or (2) describing it. (http://en.wikipedia.org/wiki/Subject_complement)