Summary:
This handout defines dependent and independent clauses and explores how they are treated in standard usage.
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.
Independent Clause
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.
Jim studied in the Sweet Shop for his chemistry quiz.
Dependent Clause
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.
When Jim studied in the Sweet Shop for his chemistry quiz . . . (What happened when he studied? The thought is incomplete.)
Dependent Marker Word
A dependent marker word is a word added to the beginning of an independent clause that makes it into a dependent clause.
When Jim studied in the Sweet Shop for his chemistry quiz, it was very noisy.
Some common dependent markers: 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.
Connecting independent clauses
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.
1. Coordinating Conjunction
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:
Jim studied in the Sweet Shop for his chemistry quiz, but it was hard to concentrate because of the noise.
2. Independent Marker Word
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.
Jim studied in the Sweet Shop for his chemistry quiz; however, it was hard to concentrate because of the noise.
Some common independent markers: also, consequently, furthermore, however, moreover, nevertheless, and therefore.
Connecting dependent and independent clauses
Subordinating conjunctions allow writers to construct complex sentences, which have an independent clause and a subordinate (or dependent) clause. Either clause can come first.
The students acted differently whenever a substitute taught the class.
Whenever a substitute taught the class, the students acted differently.
Note that the clauses are separated with a comma when the dependent clause comes first.
Some common subordinating conjunctions: after, as, before, once, since, until, and while.
Some Common Errors to Avoid
Comma Splices
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.
- 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
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.
- 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
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.
- Correct: Because I forgot the exam was today, I didn't study.
- (or) I forgot the exam was today.
Parts of speech have specific tasks to perform when they are put together in a sentence.
A noun or pronoun functions as the sentence subject when it is paired with a verb functioning as the sentence predicate.
Every sentence has a subject and predicate.
A subject can be a noun or pronoun that is partnered with an action verb.
Example:
Sometimes a verb will express being or existence instead of action.
Example:
Sometimes we use sentences in which a subject is not actually stated, but is, nevertheless, understood in the meaning.
Example:
A sentence like this gives an order or a request to someone.
Because we use such statements when we are talking directly to someone, we omit the word you. It is understood in the sentence. Therefore, in statements like this one, we say the subject is
you (understood).
This kind of sentence is an imperative sentence.
A predicate is a verb that expresses the subject's action or state of being.
Example:
Sometimes the predicate will be composed of two or three verbs that fit together - the main verb preceded by one or more auxiliary (helping) verbs.
IMPORTANT NOTE: To be a predicate, a verb that ends in -ing must ALWAYS have a helping verb with it. An -ing verb WITHOUT a helping verb cannot be a predicate in a sentence.
A subject and predicate may not always appear together or in the normal order, as the following examples show:
Phrases
A phrase is a group of related words that
1. does not express a complete thought
2. does not have a subject and predicate pair
One type of phrase is a prepositional phrase.
Examples:
Another kind of phrase is a verbal phrase.
Examples:
Even though these phrases contain nouns (pronouns) and/or verb forms, none of the nouns/pronouns/verbs are subjects or predicates. None of them work as a partnership.
Also, these phrases do NOT express complete thoughts.
Clauses
Words and phrases can be put together to make clauses.
A clause is a group of related words that contain a subject and predicate.
Note the difference between phrases and clauses in the following examples:
Only one of the clauses is a sentence.
Clause #1 gives a thought or an idea that is COMPLETE, that can stand by itself, independent of other words.
However, clause #2 gives an INCOMPLETE thought or idea, one that cannot stand by itself, one that needs some more words to make it whole. The word after changes the meaning, making the thought incomplete. After reading this clause, we are left hanging.
These two clauses illustrate the two kinds of clauses:
independent clauses and dependent clauses
An independent clause is a group of words that contains a subject, a predicate, and a complete thought.
A dependent clause is a group of words that contains a subject and a predicate, but does NOT express a complete thought.
Compounding Sentence Elements
and, but, or, and nor
may join subjects, predicates, adjectives, adverbs, prepositional phrases or dependent clauses within a sentence. This process is called "compounding."
The following examples show the process of compounding
WORDS
PHRASES
DEPENDENT CLAUSES
When entire independent clauses (simple sentences) are joined this way, they become compound sentences.
Avoiding Fragments
A complete sentence needs only two elements:
a subject - predicate unit AND a complete thought
In other words, a simple sentence is actually the SAME thing as an independent clause.
Dependent clauses or phrases are called fragments because they are missing one or more parts needed to make a sentence.
Therefore, they are only pieces or fragments of complete sentences.
Look at these examples:
Avoiding Comma Splices and Fused Sentences
Sometimes two independent clauses (simple sentences) can be joined to form another kind of sentence: the compound sentence.
Two major errors can occur when constructing compound sentences.
Error #1: The Comma Splice
Writers make this error when they try to separate the two independent clauses in a compound sentence with a comma alone.
A comma is not a strong enough punctuation mark to separate the two independent clauses by itself; thus, using it causes the clauses to be spliced together.
Example of a comma splice:
This sentence can be repaired in three ways:
1. by adding an appropriate coordinating conjunction
2. by changing the comma to a semicolon
3. by changing the punctuation and adding an appropriate conjunctive adverb
Error #2: The Fused Sentence
Writers make this error by joining two independent clauses into a compound sentence without using any punctuation between them.
No punctuation between the two independent clauses causes them to "fuse" into an INCORRECT compound sentence.
Example of a fused sentence:
This sentence is also repaired in three ways:
1. by adding a comma and an appropriate coordinating conjunction
2. by placing a semicolon between the two clauses
3. by adding the needed punctuation and an appropriate conjunctive adverb
Another way to repair a comma splice or fused sentence is to make each independent clause into a simple sentence.