•In a reply to a question, the tense of the verb in the noun clause does not change if the main verb of the completed sentence is in the simple present.
•A: How long was she there?
•B: I don't know how long she was there.
•If the main verb of the completed sentence is in the simple past, the tense of the verb in the noun clause changes.
•A: When will they arrive?
•B: Nobody told me when they would arrive.
•I don't remember who he is.
•We didn't hear what they were talking about.
•Nobody knows whether they passed .
Noun Clause as Object of a Preposition
•Everyone believes in whatever Tony says.
•I never think about how I will pay my bills.
•I can't rely on what you tell me.
Noun Clause as Adjective Complement
•A noun clause as an adjective complement completes the meaning started by the adjective.
•I'm sure that he'll succeed. (He will succeed. I'm sure of it)
•I'm convinced that she's unhappy. (She's unhappy. I'm convinced of that.)
•That is the most commonly used subordinator in this pattern. It can be omitted from the sentence.
•I'm sure he'll succeed.
•I'm convinced she's unhappy.
-ever WORDS IN NOUN CLAUSES
•I'll invite whoever (or whomever) you like.
•Whoever shows up for dinner is welcome.
•The dog will eat whatever you give her.
• Be careful not to confuse however when it is used to introduce a noun clause and however when it is used as a conjunctive adverb.
•Compare: However you cook the meat is all right with me.
•I'll help you to cook it; however, I don't like rare meat .
NOUN CLAUSES BEGINNING WITH That
•That can often be omitted when it introduces a noun clause used as object of the verb.
•We assumed our son was sick.
•I could not believe he had lied to us.
•I hope he will tell the truth soon.
•Do you imagine he knows our feelings?
•That cannot be omitted when it introduces a noun clause used as subject of the sentence. That as subject of the sentence emphasizes the information in the noun clause.
•That he had lied to us was unbelievable.
•That we accepted his apology made him feel better.
•That small boys sometimes lie should not surprise anyone.
•That as subject of the sentence is very formal. It rarely occurs in informal spoken English. Instead, in conversation, speakers of English often use the word it as subject of the sentence and place the noun clause at the end of the sentence. In this pattern, a noun clause may follow a noun, pronoun, or an adjective.
•It is a fact that the world is fighting a food shortage. (That the world is facing a food shortage is a fact.)
•It is true that many people are starving. (That many people are starving is true.)
•People also often use a noun clause beginning with the fact that as subject of the sentence in place of a noun clause beginning with that.
•The fact that everyone refused to attend the meeting took us by surprise. (That everyone refused to attend the meeting took us by surprise.)
SUBJUNCTIVE FORM OF THE VERB IN NOUN CLAUSES
• When the following verbs have a noun clause as direct object, they require the form of the verb (the infinitive without to). The use of the base form stresses the urgency or importance of the statement
•command demand insist
•propose recommend request require suggest urge
•The doctor advised that Sheila remain in the hospital .
•The nurse had insisted that Sheila's husband leave the room .
• She recommended that he return in the morning .
•The base form of the verb is used regardless of the tense of the main verb or the subject in the noun clause.
•She recommends that he be at the store as early as possible.
•She recommended that he be at the store as early as possible.
•The negative is formed by putting not before the verb in the noun clause.
•The doctor advised that Sheila not remain in the hospital.
•The nurse recommended that her husband not stay too long.
•In informal English, the auxiliary should sometimes precedes the verb in the noun clause.
•The doctor advised that Sheila should remain in the hospital.
•The nurse recommended that Sheila's husband should return in the morning.
•The auxiliary should is not used with the verbs command and demand.
•The base form of the verb is also used in noun clauses as adjective complements after these expressions: it is important that, it is necessary that, it is essential that, and it is vital that.
•It is important that either your mother or your father sign these papers.
• It was necessary that you be here at 8:30.