What is a “run-on” sentence?

From LitWiki

Run-on sentences

Run-on sentences, also known as "fused sentences", contain two independent clauses, either of which can stand by itself. When these two independent clauses are connected by a comma, it is known as a comma splice. When there is no comma, these clauses become harder to recognize. Another point about run-on sentences is that it really doesn't matter about the length of the sentence. A run-on can be a very short sentence, such as, Nothing is on television I should turn it off. Just because a sentence is very long, though, it does not necessarily mean that it is a run-on. On one of the works I have cited below will have a link to a 239 word sentence. This quite long sentence is strucually correct, although it is not something you might want to use too much on papers or on-line entries.

Avoiding Run-on sentences

There are, of course, many ways to avoid a run-on sentence. A really easy way to join the two independent clauses together is by a semicolon. When using a semicolon, though, you must remember that the two ideas have to be closely related to one another. The other way to join the two independent clauses without having a run-on is to use either coordinating conjunctions or subordinating conjunctions.

Types of Conjunctures

Coordinating Conjunctures

When using a coordinating conjunction, remeber this pattern [independent clause/ comma/ coordinating conjuntion/ indpendent clause]. Below is a list of ways to use coordinating conjunctures.

Examples

  • Use and to indicate the addition of the second independent clause.
  • Use but or yet to indicate contrast between two independent clauses.
  • Use or to indicate a choice or alternative between two independent clauses.
  • Use for to indicate that the second independent clause is the cause of the first.
  • Use so to indicate that the second independent clause is the result of the first.

Subordinating Conjunctures

With subordinating conjunctures, there are two patterns you can use. The first [independent clause/subordinating conjuncture/independent clause] and the second is [subordinating conjuncture/independent clause/comma/independent clause]. Here are some ways to use subordinating conjunctures:

Examples

  • Use after, before, once, until, when, and where to indicate time relationships.
  • Use because and since to indicate a reason.
  • Use if to indicate cause and effect.
  • Use unless to indicate a negative cause and effect.
  • Use although and (even) though to indicate "in spite of".

Work Cited

Grammar Lessons On the Web The Grammar Outlaw Run-on Sentences Writing Instruction Tutorial