Sentence Structure Errors: Run-on and Fragment Sentences: Students often make numerous sentence structure errors in their writing.  The SAT test makers know this, so they create a frequent number of their questions to assess your ability for spotting these errors. Let's take a closer look at both of these errors, focusing on the typical forms of the errors that you may encounter on the exam. 

Run-On Sentences

Run-On Sentences: Run on sentences occur for two reasons: (a) a writer fails to use correct punctuation, placing a comma between two independent clauses; (b) an author uses no punctuation between two or more clauses, leaving the reader no marks for starting and stopping.

Example for Type A: Faulty Punctuation

Jack London used the antagonistic force of nature in many of his short stories, he believed a conflict between man and nature was a timeless duel.

Notice the fracture here.  The comma used between the words "stories" and "he" is a comma splice.  Be aware of this faulty punctuation since many INCORRECT answer choices contain this fault.  Look for periods or semi-colons as elements to fix the fracture.  However, the comma may be correct if and only if the writer adds a conjunction to the sequence.  More sophisticated corrections include turning the second clause into clause or a phrase.  Consider the five different forms of corrections since all may appear as the corrected form in the answer choices:

  • stories; he (semi-colon correction)
  • stories.  He (period correction)
  • stories, for he (conjunction correction)
  • intentions since he believed …(subordinate clause correction)
  • intentions, believing a conflict … (phrase correction)

Seldom will the test maker ask you to choose one as the best correction.  What you find is more typically with run-on sentence errors is that they appear in the improving sentence error questions and there will typically only be one answer choice that contains one of the corrections above.  It seems simple why the test maker does this.  At a certain level, some run-on sentence corrections are better than others, but there are no strict rules for which one is better.  Hence, the choice is subjective, a matter of opinion.  So, look for one of the corrections, but above all be able to spot the error. 

Example Type B: No Punctuation

Walt Whitman was a great American poet he wrote a book of poetry entitled Leaves of Grass.

As you can see there are two clauses here.  One clause ends at "poet," beginning with the new clause that starts at "he."  Since there is no punctuation, this, too, is a run-on sentence.  There is no need to elaborate on various corrections since the corrections that I mentioned above apply here as well.  However, consider how to fix this sentence as well:

  • poet; he (semi-colon correction)
  • poet.  He (period correction)
  • poet, and he (conjunction correction)
  • poet who wrote a …(subordinate clause correction)
  • poet, composing a book of …(phrase correction)

Fragment Sentences

Let's also take a look at the most common types of fragment sentences.  I have identified six different forms of fragments; however, for the sake of brevity it seems useful to only cover three of the most common types of fragments that occur on the SAT.  Let's begin with a definition.  A fragment sentence is an undercooked idea; more technically speaking, it is a sequence of words that is missing a subject or a predicate (verb), or sometimes both.  Consider the following fragment types:

Phrase Fragment: 

Often times a series of phrases strung together gives the appearance of a complete thought.  For instance, take this sequence below:

During the hurricane, hiding under a table praying for the storm to pass quickly.

In this case, the sequence begins with a phrase, only to be followed by two additional phrases.  By definition, most phrases do not contain subjects and they always do not contain verbs.  This example fails to provide a subject and a verb, so it is undercooked.  Those who fail to recognize fragments might mistake "hurricane" as a subject and mistake "hiding" and "praying" as verbs, even though depending context they are either nouns or adjectives since they are what we call in grammar a verbal. 

Verb Fragment

By far, one of the most common types of fragments is the verb fragment.  The dreaded verbal causes this. In fact, I just used one "dreaded."  Verbals are words that look like verbs but they don't act like them.  For instance, I may use "dreaded" as a verb such as "I dreaded the next turn."  Or, as I used it, the word "dreaded" may be used as an adjective such as "dreaded verbal," whereby "verbal" is modified by "dreaded."  The test makers love to use verbals as a means for creating fragment sentences.  You truly need to be aware of these since they appear in both improving sentence errors and identifying sentence errors.  Consider the verb fragment below:

The troops waiting patiently for their commander.

Though the sequence does contain a subject "troops," students often mistake "waiting" for a verb; however, a closer look reveals that the word functions as an adjective, modifying "troops." 

Be aware of simple changes in the answer choices such as the change from "waiting" to "wait"; this is especially true on the improving sentence errors since the answer choice containing the correct verb is often the right answer choice.  Within identifying sentence errors, there will often be a line underneath the verbal, and you should know that this is the grammar error and hence the correct choice. 

Complex-Compound Fragment

More and more frequently, I have found this error on the exam.  After the test maker gets tired of giving you the run-around with phrase and verb fragments, they like to use a more complicated error.  Be on the lookout for this error in both the improving and identifying sentence errorsEssentially, they take half a complex sentence and half a compound sentence, smashing them together to create on giant glob of language.  Consider:

Since I had difficulty understanding the doctor's language, but the nurse made my condition much clearer to understand. 

Consider the problem here.  The subordinating conjunction "Since" creates a dependent clause until it ends at the word "language."  This first section is half of a complex sentence.  What we would expect to find, if the idea were complete, is an independent clause starting directly after the word "language."  We do not find this, and this is what causes the fragment.  Instead of an independent clause, we find a conjunction- this is no good!  Where we should find a complete sentence we receive half of a compound sentence.  This is one instance when one half plus one half does not equal a whole.  On improving sentence error choices look for answer choices that correctly subordinate or coordinate the clauses.  Simply put, look for a choice that ditches the first word or the conjunction; in this case, the word "but."  When you find this error on identifying sentence errors, look for the underlined portion to be either under the first word (subordinating conjunction) or the start of the half compound sentence which will always begin with a conjunction- for, and, but, yet, so, etc. 

The Big Seven does not exhaust all the possibilities for potential areas of grammar on the SAT exam.  For example, there are common errors of usage such as preposition errors and adjective vs. adverb distinction.  More importantly, there are illogical comparison errors as well.  The Big Seven is an overall approach.  As you begin to fine tune your skills, you will want to explore the more sophisticated areas of grammar.  The drawback is simple: you invest a lot of time for a little gain.  In other words, you may find yourself studying specialized areas of grammar, hoping by chance this appears on the exam.  Certainly a few questions will arise, but if you have failed to wire the most common areas of grammar, you will not make the gains you wish to make.  The idea is to maximize your study time.  The Big Seven is a general approach to doing well on the SAT multiple-choice section; it is not an approach for a perfect score!  Let's take a look a closer look at each individual question, concentrating on certain traits that may help you to answer the questions accurately.

Back to SAT Writing Study Guide Next - Improving Sentence Errors