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Writers' Center

Eastern Washington University

Grammar, Punctuation, and Sentences


Writing is a lot like good music. Sometimes you need to mix it up. While short, concise sentences can pack a staccato punch, sometimes you need to add a little variety to the rhythm of your writing with compound and complex sentences.

Compound Sentences

A writer creates a compound sentence by joining two complete thoughts (meaning each thought has a subject and verb, and the thoughts could stand all on their own—otherwise known as “independent clauses”).

There are several ways to correctly punctuate a compound sentence (in order to avoid a comma splice or run-on sentence).

Option #1:

Complete Thought       + Comma        + FANBOYS          + Complete Thought
He came to pick her up               ,            but           she wasn't ready yet.

Side Note: The acronym FANBOYS stands for those short connecting words (technical term: coordinating conjunctions) that you use frequently: for, and, nor, but, or, yet, so.

Option #2:

Complete Thought + Semicolon + Complete Thought
He came to pick her up ; she wasn't ready yet.

Option #3:

Complete Thought + Semicolon + Conjunctive Adverb + Comma + Complete Thought
He came to pick her up ; however , she wasn't ready yet.

Side Note: Some other examples of conjunctive adverbs are however, moreover, therefore, thus, consequently, furthermore, and unfortunately.

Option #4:

You could also use a dash (which shows emphasis) or a colon in place of the semicolon as well.

Click HERE for a refresher on how to correctly use different punctuation marks like semicolons, dashes, and colons.

Complex Sentences

A writer creates a complex sentence by joining an independent clause (or “complete thought”) and a dependent clause (a.k.a. subordinate clause).

First, let’s define “dependent clause.” It cannot stand alone as a complete sentence (even though it may contain a subject and a verb), and it begins with a subordinating conjunction (because, when, while, after… and many more).

Side Note: If a dependent clause comes first, a comma should follow it. No comma needed if the independent clause comes first (unless you’re trying to show contrast between the two clauses).

For example...

Dependent Clause + Comma + Independent Clause
While I checked my text messages , she proofread our group project.
Independent Clause + NO Comma + Dependent Clause
She proofread our group project   while I checked my text messages.