Clauses are combined in three different ways: coordination, subordination, and by means of a semicolon.
Coordination involves joining independent clauses with one of the coordinating conjunctions: and, but, or, nor, for, yet, and sometimes* so. "Ramonita thought about joining the church choir, but she never talked to her friends about it."
Subordination involves turning one of the clauses into a subordinate element (one that cannot stand on its own) through the use of a Subordinating Conjunction (sometimes called a dependent word) or a Relative Pronoun.
"Although Ramonita often thought about joining the choir, she never talked to her friends about it."
"Yasmin is Ramonita's sister. Yasmin told Ramonita to join the choir no matter what her friends said."
Joining these with the use of a relative clause:
"Yasmin, [who is] Ramonita's sister, told Ramonita to join the choir."
Semicolons can connect two independent clauses with or without the help of a conjunctive adverb (transitional expression). "Ramonita has such a beautiful voice; many couples have asked her to sing at their wedding."
Non-restrictive relative clauses (also known as non-defining relative clauses) provide non-essential information about the antecedent in the main clause. The information is not crucial for understanding the sentence's meaning correctly and can be omitted without affecting the sentence's meaning. In other words, non-restrictive relative clauses are an aside that adds extra information.
"The science fair, WHICH lasted all day, ended with an awards ceremony."
"The theater, in WHICH the play debuted, housed 300 people."
Restrictive relative clauses (also known as defining relative clauses) add essential information about the antecedent in the main clause. The information is crucial for understanding the sentence's meaning correctly and cannot be omitted. In other words, without the restrictive relative clause, the sentence does not make sense.
"This is the house THAT had a great Christmas decoration."
"It took me a while to get used to people WHO eat popcorn during the movie."
Clauses are also classified as restrictive and nonrestrictive clauses. (The words essential and nonessential are sometimes used and mean the same thing as restrictive and nonrestrictive, respectively.) A nonrestrictive clause is not essential to the meaning of the sentence; it can be removed from the sentence without changing its basic meaning. Nonrestrictive clauses are often set apart from the rest of the sentence by a comma or a pair of commas (if it's in the middle of a sentence).
Professor Villa, who used to be a secretary for the President, can type 132 words a minute.
A relative [adjective] clause will begin with a relative pronoun [such as who, whom, whose, which, or that] or a relative adverb [when, where, or why]. Here are some examples: "whom Mrs. Russell hit in the head with a chalk eraser"
Whom = relative pronoun; Mrs. Russell = subject; hit = verb.
You must connect them to main clauses to finish the thought. Punctuating relative clauses can be tricky. You have to decide if the relative clause is essential or nonessential and then use commas accordingly.
Adverb clauses "modify verbs, adjectives, or other adverbs" (Mayfield). They often begin with words such as after, although, as, because, even though, unless, until, whether, and while. For example:
"After the inspector uses a dye to reveal imperfections in the metal, she examines the turbine under a magnifying class and black light." (The dependent clause was made from "The inspector uses a dye to reveal imperfections in the metal.")
Noun clauses perform the same functions in sentences that nouns do:
A noun clause can be a subject of a verb: "What Billy did shocked his friends."
A noun clause can be an object of a verb: "Billy’s friends didn’t know that he couldn’t swim."
A noun clause can be a subject complement: "Billy’s mistake was that he refused to take lessons."
A noun clause can be an object of a preposition: "Mary is not responsible for what Billy did."
A noun clause (but not a noun) can be an adjective complement: "Everybody is sad that Billy drowned."
There are at least three types of dependent clauses: noun clauses, adjective clauses, and adverbial clauses.
In contrast, a subordinate or dependent clause does not express a complete thought and therefore is not a sentence. A subordinate clause standing alone is a common error known as a sentence fragment.
An independent clause, along with having a subject and verb, expresses a complete thought and can stand alone as a coherent sentence.