The Complete Sentence
A complete sentence has two characteristics:
First, it includes an end mark — either a period [ . ], semi-colon [ ; ], question mark [ ? ], or exclamation point [ ! ].
Most importantly, the complete sentence must contain at least one independent clause. Each independent clause contains at least one independent subject and verb and expresses a complete thought.
Check out these examples:
The banana rotting at the bottom of Jimmy's book bag has soaked his biology notes with ooze.
Did you notice the cricket swimming in your cup of tea?
I cannot believe that you tried one of those disgusting chocolate-broccoli muffins!
If an independent clause exists in the sentence, you can attach whatever other sentence elements you need. Look at the additions to the independent clause below. All of the additions keep the original independent clause intact.
Independent clause: A bumblebee flew into Peter's open mouth.
Buzzing around the picnic table, a bumblebee flew into Peter's open mouth.
A bumblebee flew into Peter's open mouth, stinging the poor boy's tongue, which swelled up as big and as blue as an eggplant.
Because it smelled the peach-flavored bubble gum, a bumblebee flew into Peter's open mouth.
A bumblebee flew into Peter's open mouth and tickled the poor boy's tonsils.
Taking a wrong turn, a bumblebee flew into Peter's open mouth, but it buzzed back out before Peter swallowed.
Sometimes you might have text that concludes with an end mark that doesn’t have all of the elements of an independent clause anywhere in the sentence. When this happens, you have written a fragment, a major error in writing.
Here are some examples of fragments:
Because hungry sharks flashed on the surface of the waves.
Spilling the hot spaghetti sauce all over his new suede shoes.
To buy nice jewelry for his greedy girlfriend Gloria.
For example, a mailbox stuffed with bills, two dozen messages on the answering machine, an uppity cat, and a dead lawn.
And peeked into the room, risking the wrath of Mrs. Mauzy, who has no patience for students walking into class late.
Read the revisions below. You will see that adding an independent clause completes the thought (subjects and verbs underlined):
Because hungry sharks flashed on the surface of the waves, Mike and Sarah decided to return their surfboards to the car.
Leonardo grabbed the pot handle with his bare hands, spilling the hot spaghetti sauce all over his new suede shoes.
Danny sold half of his comic book collection to buy nice jewelry for his greedy girlfriend Gloria.
For example, April found a mailbox stuffed with bills, two dozen messages on the answering machine, an uppity cat, and a dead lawn.
Sherry turned the doorknob and peeked into the room, risking the wrath of Mrs. Mauzy, who has no patience for students walking into class late.