Avoiding Sentence Errors: Correcting Fragments, Run-Ons, Misplaced and Dangling Modifiers

I. Introduction

It is important for us to know how to avoid these kind of sentence errors like sentence fragments, run-ons, misplaced and dangling modifiers. But let’s define what are these first. Fragments are incomplete sentences that are presented as complete sentences. Run-ons are two or more sentences that have been incorrectly joined. Dangling modifiers are misplaced parts of a sentence that usually end up causing confusion in readers.
II. Content
Sentence fragments are another common error.   A sentence fragment is a group of words, not a complete sentence.   Remember that to be a complete sentence, a group of words must have a subject and a verb and must express a complete idea.   Thus a group of words must not depend on the sentence before it or after it to provide a complete idea.
Incorrect Examples:

Ran to the car. (This is a fragment that is lacking a subject.)
The woman at the bus stop. (This is a fragment that is lacking a main verb.)
Behaving badly. (This is a fragment that is lacking a subject or a main verb.)
When one of the car's tires went flat. (This is a subordinate clause.)
Correcting Fragments
Created when phrases and subordinate clauses are punctuated as if they were complete sentences, fragments can be corrected by adding the information that is missing. To rectify fragments, add a subject to the sentence that is missing a subject, add a verb to the sentence that is missing a verb, and connect a subordinate clause to a main clause to create a complete sentence. The following examples are the previous fragments corrected to read as complete sentences:
Incorrect: Ran to the car.
Correct: She ran to the car.
Incorrect: The woman at the bus stop.
Correct: The woman stood at the bus stop.
Incorrect: Behaving badly.
Correct: The students were behaving badly.
Incorrect: When one of the car's tires went flat.
Correct: When one of the...