Noun Clause. Another type of Subordinate Clause. Functions as a noun It can do anything a noun can do It can act as a subject, a direct object, a predicate nominative, an indirect object, or the object of a preposition It can appear at the beginning, middle, or end of a sentence.
Another type of Subordinate Clause
Whoever was stealing the precious stones had many accomplices. [subject]
Detectives believed they would never know what happened to the diamonds [direct object]
The anonymous midnight call was what tipped off the police. [Predicate nominative]
The lawyer instructed Betty to testify truthfully about whether she knew the suspect. [object of a preposition]
As you write, you don’t have to identify how noun clauses function in sentences. Think of them as just another tool to express ideas and vary sentence structure.
Sometimes, the introductory word of a noun clause is omitted because it is understood. The sentences below make sense if you read them with or without the bracketed word.