Sentence BoundariesWhere one sentence ends and another begins

Review

The SentenceIn a previous module, we learned that a sentence has two parts:1. A subject2. A verb

The subject is the person or thing completing the action (always a noun or pronoun) while the verb is the action being completed.

Being able to identify the subject and the verb of a sentence is how you will avoid the boundary errors we discuss in this lesson.

Types of Sentence Boundary Errors

BoundariesThe types of errors we’ll learn about in this module are called sentence boundary errors because they are errors that go beyond the boundaries of a single sentence. In other words, they contain more than one subject and verb.

There are two types of errors we’ll cover:1. Fused Sentences2. Comma Splices

Fused SentencesFused sentences are those that combine two independent clauses without any punctuation. They are also called run-on sentences.

I had a ton of homework for math last night I stayed up late to finish it all.

In this example, two independent clauses – or complete sentences – are combined incorrectly. We can recognize that by identifying the subjects and verbs.

More on Fused SentencesI had a ton of homework for math last night I stayed up late to finish it all.

This example contains two subjects and two verbs:1. I had2. I stayed

That means we have two complete sentences. 3. I had a ton of homework for math last night.4. I stayed up late to finish it all.

Without punctuation, this is a fused sentence. It goes beyond the limits of sentence boundaries.

Comma SplicesOur second sentence boundary error is called a comma splice. Like a fused sentence, a comma splice contains two independent clauses. Instead of no punctuation, however, a comma splice error incorrectly uses a comma to separate the two clauses.

I had a ton of homework for math last night, I stayed up late to finish it all.

Once again, here we have two independent clauses, but this time, the clauses are “spliced” with a comma. This, too, goes beyond the limits of sentence boundaries. We cannot connect to independent clauses with only a comma.

Correcting Boundary ErrorsCorrecting errors with sentence boundaries is easy. We have four options:

1. Separate the clauses with a period2. Separate the clauses with a semicolon3. Connect the clauses with a comma and a FANBOYS4. Connect the clauses with a subordinating conjunction

Let’s take a closer look at each of these options.

Separate the Clauses with a PeriodThis is the simplest option. Separate the clauses by placing a period between them.

I had a ton of homework for math last night. I stayed up late to finish it all.

Separate the Clauses with a SemicolonIn most cases (though not all), a semicolon works just like a period. Many students have trouble with semicolons, but remembering this rule will help you use them correctly.

I had a ton of homework for math last night; I stayed up late to finish it all.

Semicolons should be used sparingly. They are most often employed when there is a clear relationship between the two clauses, such as a comparison or a contrast.

You can learn more about semicolons in section 40 of your Little, Brown Brief (pages 322 -326).

ForAndNorButOrYetSo

FANBOYS is an acronym to help you remember a set of words called coordinating conjunctions. These words, when combined with a comma, allow you to connect to independent clauses.

I had a ton of homework for math last night, so I stayed up late to finish it all.

By adding the comma and the FANBOYS, we have corrected the sentence boundary error by correctly combining the sentences. Remember the acronym!

Connect the Clauses with a Comma + a FANBOYS

Warning! You must think carefully when working with FANBOYS. While these words do function with a comma to connect two independent clauses, that does NOT mean you will always place a comma before them. Sometimes, these words are not used in this way.

I bought milk and bread at the store yesterday. I finished my math homework but not my physics homework.

A FANBOYS only needs a comma before it when the clauses that come before and after are BOTH independent. Here, the clauses before the FANBOYS are independent, but the clauses following them are not. Neither contain a subject. In these cases, no comma is needed. We’ll return to this rule in an upcoming module.

More on FANBOYS

Connect the Clauses with a Subordinating ConjunctionIn a previous module, you learned that subordinating conjunctions indicate a dependent clause, which MUST be attached to an independent clause. The final way to correct a sentence boundary error is to make one of your clauses dependent on the other.

Since I had a ton of homework for math last night, I stayed up late to finish it all.

By adding the word “since” to the first clause, we have made this clause dependent, so it can correctly be connected with the second clause. There are several subordinating conjunctions. Refer to the module on clauses for a list or to page 196 of your Little, Brown Brief.

Let’s Review!

Sentence Boundary Errors

Incorrectly combine two independent clauses

A fused sentence is one with no punctuation at all

A comma splices incorrectly separates the clauses with only a coma

Corrections Separate the clauses with a

period Separate the clauses with a

semicolon Connect the clauses with a

comma + a FANBOYS Connect the clauses with a

subordinating conjunction

Additional ResourcesTo learn more about sentence boundary errors:

See section 36 (pages 290 -295) in your Little, Brown Brief

See the Purdue Online Writing Lab resource on clauses. Click here to visit the page (opens in new window). <http://owl.english.purdue.edu/owl/resource/598/02/