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Some sentences need more than a single noun to name an idea. Instead of saying “the reason” or “the answer,” English often uses a whole clause: “why she left,” “what the answer is,” or “that the meeting was canceled.” These word groups are called noun clauses. They have their own subject and verb, but they work inside a larger sentence as one noun-like unit. This article explains how noun clauses are built, where they appear, and how to use them clearly in writing and speech.
Contents
- Noun Clauses, Plainly Defined
- Common Noun-Clause Openers
- Using Noun Clauses as Subjects
- Using Noun Clauses as Direct Objects
- Using Noun Clauses as Indirect Objects
- Using Noun Clauses as Subject Complements
- Using Noun Clauses after Prepositions
- A Closer Look at That-Clauses
- Wh-Clauses and Embedded Questions
- Clauses Introduced by If and Whether
- How Noun Clauses Differ from Other Dependent Clauses
- Try It Yourself
Noun Clauses, Plainly Defined
A noun clause is a dependent, or subordinate, clause that does the job of a noun. It includes both a subject and a verb, yet it is not a complete sentence by itself. Instead, it fits into a larger sentence and fills a noun position, such as subject, object, complement, or object of a preposition.
Simple noun: "Maya understood the problem."
Noun clause: "Maya understood what the problem was."
In these two examples, the bold words receive the action of "understood." The clause "what the problem was" works the same way as the noun phrase "the problem." It answers the question "What did Maya understand?"
Main Features to Look For
- Can often be tested by replacing it with a pronoun such as it, this, or something
- Works as a noun: subject, object, complement, or object of a preposition
- Has a subject and a verb inside it
- Usually starts with a recognizable introductory word
- Does not stand alone as a complete sentence
Common Noun-Clause Openers
Noun clauses commonly begin with these groups of words:
| Category | Words | Example |
|---|---|---|
| That | that | "We heard that the store had closed." |
| Wh-words | what, who, whom, which, whose | "Do you know whose bag this is?" |
| Wh-adverbs | when, where, why, how | "The guide showed us where the trail begins." |
| If/Whether | if, whether | "No one knew if the office was open." |
| -ever words | whatever, whoever, whichever, wherever, whenever, however | "Whatever you choose is fine with me." |
Using Noun Clauses as Subjects
A noun clause can appear at the beginning of a sentence and act as the subject, just as an ordinary noun can:
"What the witness remembered changed the case." (What changed the case? → What the witness remembered.)
"That the roads flooded overnight delayed the buses."
"Whether the team can recover is still uncertain."
"How the painting disappeared remains unclear."
"Whoever submits the best design will receive a bonus."
When the subject is a noun clause, the main verb agrees with the clause as one singular unit: "What this room needs is better lighting" (not "are").
Putting “It” in the Subject Position
English speakers often place "it" at the start of the sentence and move the longer noun clause to the end. This usually makes the sentence easier to read:
Noun clause first: "That the concert sold out was surprising."
With "it": "It was surprising that the concert sold out."
Both versions are grammatical. In ordinary conversation and much everyday writing, the version with "it" often sounds more natural because the main verb arrives sooner.
Using Noun Clauses as Direct Objects
Noun clauses most often appear as direct objects after verbs such as know, believe, think, say, tell, realize, understand, hope, wish, doubt, discover, notice, remember, forget:
"Carlos believes that the repairs will be finished soon."
"Nina remembers where she parked the car."
"The engineers found out what had caused the outage."
"My neighbor asked whether we had seen her cat."
"They forgot how cold the cabin gets at night."
Using Noun Clauses as Indirect Objects
Noun clauses can also be indirect objects, though this pattern is not as common:
"Send whoever registered late a reminder." (Send a reminder to whom? → Whoever registered late.)
"The coach offered whoever showed up early extra practice time." (Offered extra practice time to whom?)
Using Noun Clauses as Subject Complements
After a linking verb, a noun clause may identify, rename, or explain the subject:
"The issue is that the files were never backed up."
"Our choice is whether we delay the launch."
"Her main worry is how the news will affect morale."
"A safe place is wherever you can rest without fear."
Using Noun Clauses after Prepositions
A noun clause may also function as the object of a preposition:
"I was surprised by what you told the committee."
"Marcus is uncertain about whether the train stops here."
"The scholarship will go to whoever writes the strongest essay."
"They disagreed over who should speak first."
A Closer Look at That-Clauses
Clauses that begin with "that" are among the most frequent noun clauses in English. In this use, "that" is a subordinating conjunction, not a pronoun. It introduces the clause, but it does not serve as the subject, object, or complement inside that clause.
Leaving Out “That”
When a that-clause is the direct object of a verb, speakers often drop "that" and keep the same meaning:
"We hope (that) the weather improves." — Either version works.
"Lena mentioned (that) she might arrive late." — "That" is optional.
Still, "that" is usually better left in place when:
- The clause comes after a gap or interruption: "The manager assured the staff that schedules would be posted soon."
- The sentence contains more than one related clause: "He reported that the shipment was late and that customers had been notified."
- The clause acts as the subject: "That the door was unlocked seemed strange." (Without "that," the sentence is harder to follow.)
Wh-Clauses and Embedded Questions
Noun clauses introduced by question words—who, what, where, when, why, how, which, and whose—often form embedded questions. The key rule is simple: embedded questions use statement word order, not question word order.
Direct question: "Why did the alarm ring?" (question word order)
Embedded question: "We discovered why the alarm rang." (statement word order)
Direct question: "Where is the station?"
Embedded question: "Can you tell me where the station is?"
Common Error: Avoid question word order inside embedded questions. Write "I don't know where she went" rather than "I don't know where did she go." Write "He asked what the password was" rather than "He asked what was the password."
Clauses Introduced by If and Whether
"If" and "whether" introduce noun clauses that come from yes/no questions:
Yes/no question: "Is the library open?"
Noun clause: "I don't know if the library is open." / "I don't know whether the library is open."
In many sentences, either "if" or "whether" is acceptable. Use "whether" especially in these cases:
- With "or not" immediately after it: "Whether or not the vote passes..." (Not "if or not...")
- After a preposition: "There was a debate about whether to expand the program..." (Not "about if...")
- When the clause is the subject: "Whether the guests arrive early depends on traffic." (Not "If the guests arrive early depends...")
How Noun Clauses Differ from Other Dependent Clauses
| Clause Type | Function | Example |
|---|---|---|
| Noun clause | Works as a noun | "She noticed that the window was open." (object) |
| Adjective clause | Describes or identifies a noun | "The student who won the award gave a speech." (modifies "student") |
| Adverb clause | Modifies a verb or a whole clause | "We stayed inside because the storm grew worse." (modifies "stayed") |
A quick substitution test helps. If the clause can be replaced by a pronoun such as it or something, it is probably a noun clause. If it behaves more like an adjective or an adverb, then it is an adjective clause or an adverb clause.
Try It Yourself
Find the noun clause in each sentence, then name its function:
- "What the researcher found surprised the panel."
- "The instructor demonstrated how the software works."
- "The difficulty is that nobody has the original file."
- "We're still thinking about what comes next."
- "Whether the proposal passes depends on the final vote."
- "Give whoever arrives first the front-row seat."
Answers: 1. "What the researcher found" — subject. 2. "how the software works" — direct object. 3. "that nobody has the original file" — subject complement. 4. "what comes next" — object of preposition "about." 5. "Whether the proposal passes" — subject. 6. "whoever arrives first" — indirect object.
Key Takeaway: A noun clause is a dependent clause that acts like a noun. It may be a subject, direct object, indirect object, subject complement, or object of a preposition. Watch for openers such as "that," "what," "who," "whether," "if," "how," and other wh-words. Once you recognize noun clauses, you can report speech, include indirect questions, and express fuller ideas without losing sentence control.