A noun clause serves the purpose of a noun. That means it can be the subject or object of a verb. It can also be the object of a preposition.

A noun clause is a kind of subordinate clause. It is usually introduced by the conjunction that. It can also be introduced by other conjunctions like if, whether, who, where, when, what etc.

Study the following sentences.

• Do you know him?

This is a simple sentence because it has just one finite verb – knows.

It can be converted into a complex sentence by expanding the noun him to a noun clause.

• Do you know who he is?

Here the noun clause ‘who he is’ is the object of the verb know.

More examples are given below.

• I do not know his place of residence.

This simple sentence can be converted into a complex sentence by expanding the noun phrase ‘his place of residence’ into a noun clause.

• I don’t know where he resides. OR I don’t know where he lives.

Here the noun clause ‘where he lives’ is the object of the verb know.

• She hopes to win the first prize.

Here the noun phrase ‘to win the first prize’ is the object of the verb hopes. By expanding it into a noun clause, we can change the sentence into a complex sentence.

• She hopes that she will win the first prize.

• Nobody knows the truth. (Simple sentence)
• Nobody knows what the truth is. (Complex sentence)
• He seems to be crazy. (Simple sentence)
• It seems that he is crazy. (Complex sentence)
• Everybody knows about his involvement in the conspiracy. (Simple sentence)
• The fact that he is involved in the conspiracy is known to everybody. (Complex sentence)
• Listen to me. (Simple sentence)
• Listen to what I say. (Complex sentence)
• I do not know the time of his arrival. (Simple sentence)
• I do not know when he will arrive. (Complex sentence)

• Keep hitting the gong hourly.
(normal adverb)
• Keep hitting the gong until I tell you to stop.
(adverbial clause)

Adverbs of Time

• After the game has finished, the king and pawn go into the same box. (Italian Proverb)
• I stopped believing in Santa Claus when my mother took me to see him in a department store, and he asked for my autograph. (Shirley Temple)
• As soon as you trust yourself, you will know how to live. (Johann Wolfgang von Goethe)

Adverbs of Place

• In a world where there is so much to be done, I felt strongly impressed that there must be something for me to do. (Dorothea Dix)
• I am not afraid of the pen, the scaffold, or the sword. I will tell the truth wherever I please.

Adverbs of Manner

• He acts like it is a joke.
• We don't have conversations. You talk at me the way a teacher talks to a naughty student.
• Except for an occasional heart attack, I feel as young as I ever did.

Adverbs of Degree or Comparison

• A vacuum is a hell of a lot better than some of the stuff that nature replaces it with. (Tennessee Williams)
• He is as smart as he is tall.
• She is not so bright as she thinks she is.

• You are taller than I.
(In this example, the verb am has been omitted. This is permissible.)
• You are taller than I am.
(This is the full version.)
• You are taller than me.
(This is the colloquial version. This version might irk some of your grammar-savvy readers, but it is acceptable.)

Adverbs of Condition

• If the facts don't fit the theory, change the facts. (Albert Einstein)
• If the English language made any sense, a catastrophe would be an apostrophe with fur.
• If all the rich people in the world divided up their money among themselves, there wouldn't be enough to go around.

Adverbs of Concession

• Although golf was originally restricted to wealthy, overweight Protestants, today it's open to anybody who owns hideous clothing.
• A loud voice cannot compete with a clear voice, even if it's a whisper.

Adverbs of Reason

• I don't have a bank account, because I don't know my mother's maiden name. (Paula Poundstone)
• Since you are like no other being ever created since the beginning of time, you are incomparable.

Properties of an Adverbial Clause

• An adverbial clause is an adjunct. This means it can be removed without the sentence being grammatically wrong.
• An adverbial clause is a dependent clause. This means it cannot stand alone as meaningful sentence in its own right.
• An adverbial clause usually starts with a subordinating conjunction (e.g., although, because, if, until, when)
• An adverbial clause will contain a subject and a verb. (This is what makes it a clause as opposed to a phrase.)