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Reading Writing Center | Microlab 9


Microlab 9 - Run On Sentences

Readers tend to trust writers who use language with skill and precision. Readers can be misled and confused by errors in grammar and mechanics.

This microlab will help you:

  • -understand correct ways of joining and separating distinct sentences
  • -recognize run-on sentences and comma splices
  • -repair run-ons and comma splices

Review of Distinct Sentences

Here are two complete sentences:

Emiko pulled back the heavy curtains.
Sunlight streamed into the room.

What happens if we try to join these sentences without using correct punctuation or connecting words?

Emiko pulled back the heavy curtains, sunlight streamed into the room.

This sentence error is called a comma splice. A comma splice incorrectly joins two independent clauses with only a comma. In order to fix a comma splice, a connecting word must be used.

A clause is a group of words containing a subject and a predicate. There are two types of clauses that we need to be familiar with in order to correct run-on sentences and comma splices: an independent clause and a dependent clause.

independent clause: a group of words containing a subject and a predicate that forms a complete thought and can stand on its own

dependent clause: a group of words containing a subject and a predicate that does not form a complete thought and cannot stand on its own

These same clauses can be used to illustrate a run on sentence. What if we didn’t put any punctuation between these clauses?

Emiko pulled back the heavy curtains sunlight streamed into the room.

This is called a run-on sentence. A run-on sentence combines two independent clauses without any punctuation. Since the two clauses each form a complete thought, they need to be separated by proper punctuation.

So how can we repair the confusing string of words: Emiko pulled back the heavy curtains, sunlight streamed into the room? The following suggestions will help you repair this sentence by using either independent clauses or dependent clauses.

In order to understand how to correct these clauses, let’s quickly review some rules for clauses (not to be confused with Santa Clause):

  • - You can combine two independent clauses when you use correct punctuation.
  • - You can combine a dependent clause and an independent clause.
  • - You simply can use an independent clause as a full sentence.
  • - You cannot join two dependent clauses to make a full sentence.
  • - You cannot let a dependent clause stand alone as a sentence.

I. Repairs for Independent Clauses in Run-On Sentences

Repair 1. Use a period to separate the clauses.

Emiko pulled back the heavy curtains.  Sunlight streamed into the room.

Repair 2. Use a semicolon to separate the clauses.

Emiko pulled back the heavy curtains; sunlight streamed into the room.

Repair 3. Use a comma and a connecting word such as and, so, or but.

Emiko pulled back the heavy curtains, and sunlight streamed into the room.

*Words like and, so, and but are called coordinating conjunctions.

II. Repairs for Dependent Clauses in Run-On Sentences

-->Be careful with the connecting words you choose because they can vary the meaning of the sentence.

Repair 4. Use a semicolon followed by a conjunctive adverb like finally, nonetheless, or however and a comma:

Emiko pulled back the heavy curtains; finally, sunlight streamed into the room.

Repair 5. Use a conjunction like until, because, or if to join the clauses.

Emiko pulled back the heavy curtains until sunlight streamed into the room.

*Words like until, because, and if are called subordinating conjunctions.

Repair 6. Use a connecting word like who, which, or that to join the clauses.

Emiko pulled back the heavy curtains that kept sunlight from streaming into the room.

**Notice that a few other words in the sentence change when one of these connecting words is used. Connecting words like who, which, and that are called relative pronouns.

Review:

Let’s practice each of these six techniques for joining clauses correctly. Here are several run-on errors. Notice that a dot ( • ) stands between each of the two clauses. Repair these run-ons using the methods described above.

Practicing Repair 1:

We all saw the comet • it blazed for more than three seconds in the sky.

This run-on can be repaired by a period:

We all saw the comet.  It blazed for more than three seconds in the sky.

Practicing Repair 2:

The books spilled from the shelves • loose pages scattered in the howling wind.

This run-on can be repaired by a semicolon:

The books spilled from the shelves; loose pages scattered in the howling wind.

Practicing Repair 3:

Pastries sounded delicious for breakfast • they weren’t nutritious.

Use a comma and a coordinating conjunction between these two clauses:

Pastries sounded delicious for breakfast, but they weren’t nutritious.

Practicing Repair 4:

The runner felt faint • he was determined to finish the marathon.

Use a semicolon followed by a conjunctive adverb and a comma:

The runner felt faint; nevertheless, he was determined to finish the marathon.

Practicing Repair 5:

Dandelions covered the hillside • the new homes were built there.

Use a subordinating conjunction to connect these two clauses:

Dandelions covered the hillside before the new homes were built there.

Practicing Repair 6:

We met the woman • she founded Mercy Hospital.

Use a relative pronoun to connect these two clauses:

We met the woman who founded Mercy Hospital.

The relative pronoun “who” replaces “she” in the original sentence above.

KEY POINTS TO REMEMBER:

  • A comma splice uses a comma to incorrectly join two independent clauses.
  • A run-on sentence does not use any punctuation to join two independent clauses.
  • Both are incorrect because they do not properly separate each complete idea.
  • *A comma itself does not repair a run-on error.

    *Use one of these techniques for joining or separating clauses:

    1. 1. a period
    2. 2. a semicolon
    3. 3. a comma and a coordinating conjunction
    4. 4. a semicolon, conjunctive adverb and comma
    5. 5. a subordinating conjunction
    6. 6. a relative pronoun

    *A clause contains a subject and a verb.

    *A comma by itself CANNOT be used to join two clauses together to make a sentence.