Clauses

When you want to use commas and semicolons in sentences and when you are concerned about whether a sentence is or is not a fragment, a good way to start is to be able to recognize dependent and independent clauses. The definitions offered here will help you with this.

An independent clause is a group of words that contains a subject and verb and expresses a complete thought. An independent clause is a sentence.
 * Independent Clause**

//Jim studied in the Sweet Shop for his chemistry quiz.//

A dependent clause is a group of words that contains a subject and verb but does not express a complete thought. A dependent clause cannot be a sentence. Often a dependent clause is marked by a dependent marker word.
 * Dependent Clause**

// When Jim studied in the Sweet Shop for his chemistry quiz. . . (What happened when he studied? The thought is incomplete.)//

A dependent marker word is a word added to the beginning of an independent clause that makes it into a dependent clause.
 * Dependent Marker Word**

// When Jim studied in the Sweet Shop for his chemistry quiz, it was very noisy.//

Some common dependent markers are: after, although , as , as if , because , before , even if , even though , if , in order to , since , though , unless , until , whatever , when , whenever , whether , and while.

There are two types of words that can be used as connectors at the beginning of an independent clause: coordinating conjunctions and independent marker words.
 * Connecting dependent and independent clauses**

The seven coordinating conjunctions used as connecting words at the beginning of an independent clause are and, but , for , or , nor , so , and yet. When the second independent clause in a sentence begins with a coordinating conjunction, a comma is needed before the coordinating conjunction:
 * 1. Coordinating Conjunction**

//Jim studied in the Sweet Shop for his chemistry quiz, but it was hard to concentrate because of the noise.//

An independent marker word is a connecting word used at the beginning of an independent clause. These words can always begin a sentence that can stand alone. When the second independent clause in a sentence has an independent marker word, a semicolon is needed before the independent marker word.
 * 2. Independent Marker Word**

//Jim studied in the Sweet Shop for his chemistry quiz; however, it was hard to concentrate because of the noise.//

Some common independent markers are: also, consequently , furthermore , however , moreover , nevertheless , and therefore.

Some Common Errors to Avoid
A comma splice is the use of a comma between two independent clauses. You can usually fix the error by changing the comma to a period and therefore making the two clauses into two separate sentences, by changing the comma to a semicolon, or by making one clause dependent by inserting a dependent marker word in front of it. //Incorrect: I like this class, it is very interesting.//
 * Comma Splices**
 * //Correct: I like this class. It is very interesting.//
 * //(or) I like this class; it is very interesting.//
 * //(or) I like this class, and it is very interesting.//
 * //(or) I like this class because it is very interesting.//
 * //(or) Because it is very interesting, I like this class.//

Fused sentences happen when there are two independent clauses not separated by any form of punctuation. This error is also known as a run-on sentence. The error can sometimes be corrected by adding a period, semicolon, or colon to separate the two sentences. //Incorrect: My professor is intelligent I've learned a lot from her.//
 * Fused Sentences**
 * //Correct: My professor is intelligent. I've learned a lot from her.//
 * //(or) My professor is intelligent; I've learned a lot from her.//
 * //(or) My professor is intelligent, and I've learned a lot from her.//
 * //(or) My professor is intelligent; moreover, I've learned a lot from her.//

Sentence fragments happen by treating a dependent clause or other incomplete thought as a complete sentence. You can usually fix this error by combining it with another sentence to make a complete thought or by removing the dependent marker. //Incorrect: Because I forgot the exam was today.//
 * Sentence Fragments**
 * Correct: Because I forgot the exam was today, I didn't study.
 * (or) I forgot the exam was today.