This simply means that some clauses can stand by themselves, as separate sentences, and some can't. The subordinate clause is created by a subordinating conjunction or dependent word . Clauses are also classified as restrictive and nonrestrictive clauses. Professor Villa, who used to be a secretary for the President , can type 132 words a minute. Review the Notorious Confusables section on the difference between That and Which for additional clarification on the distinction between restrictive and nonrestrictive .
Relative clauses can be either restrictive or nonrestrictive.
Giuseppe said that the plantar wart, which had been bothering him for years , had to be removed . Charlie didn't get the job in administration, which really surprised his friends . Charlie didn't get the job in administration, and he didn't even apply for the Dean's position, which really surprised his friends . A relative clause that refers to or modifies entire clauses in this manner is called a sentential clause . The ability to recognize a clause and to know when a clause is capable of acting as an independent unit is essential to correct writing and is especially helpful in avoiding sentence fragments and run-on sentences. .