What is a Complete Sentence?

A complete sentence is a sentence that communicates a fully formed thought and contains both a subject (actor) and a verb (action). A complete sentence is also known as an independent clause because it can stand alone and function independently.

Examples of complete sentences (independent clauses):

• “I enjoyed going to the rodeo last weekend.” This sentence has a subject (“I”) and a verb (“enjoyed”).
• “My best friends and I are traveling to Greece in July.” This sentence contains a subject (“my best friends and I”) and a verb (“are traveling”).

On the other hand, dependent clauses are not fully formed thoughts even though they contain subjects and verbs. Dependent clauses begin with a subordinate conjunction (such as “when,” “if,” or “as”). These subordinate conjunctions function as roadblocks to the dependent clause being an independent clause.

Examples of dependent clauses:

• “If (subordinate conjunction) you were going to jump in the puddle.” Even though it has a subject (“you”) and a verb (“were going”), this sentence is incomplete due to the subordinate conjunction “if.”
• “When (subordinate conjunction) we arrive at the concert.” This sentence is also incomplete because of the subordinate clause “when.”

Dependent clauses must be paired with an independent clause for them to function:

• “If you were going to jump in the puddle (dependent clause), you should have taken off your nice clothes first (independent clause).”
• “When we arrive at the concert (dependent clause), we should find our seats first thing (independent clause).”

Now these sentences can function because they have an independent clause to help the dependent clause.

Sentence Fragment

A sentence fragment refers to a sentence that is not a complete thought; it doesn’t make sense on its own and lacks one of the key components of a complete sentence, making it ”fragmented” or an incomplete sentence.

The previous section focused on one type of fragment: dependent clauses (which do not have independent clauses to help them). However, dependent clauses are not the only types of fragments. Any sentence that is missing a subject or verb is a fragment.

Examples of fragments:

• “Running to the store.” This sentence is missing a subject.
• “Sarah’s great-aunt who lives in Virginia.” This sentence is missing a verb.

The main reason that people overlook a sentence fragment in their writing is because they spot a phrase that looks like a subject or verb but actually isn’t. In the second example above, some might say that ”lives” is the verb in the sentence. However, the verb ”lives” is a part of a phrase describing ”Sarah’s great-aunt” and not the subject of the whole sentence. To convey this idea as a complete sentence, the writer would need to say “Sarah’s great-aunt lives in Virginia.”

Correcting Fragments

In order to correct a sentence fragment, the writer must first identify what is missing in the sentence. Is it missing a subject, verb, or just a complete thought altogether? After identifying what is missing, the writer should add that information to the sentence.

The previous examples of fragments could be corrected as such:

• “Abdullah is running to the store.” Now the sentence has a subject (“Abdullah”).
• “Sarah’s great-aunt who lives in Virginia came to visit last week.” Now the sentence has a verb (“came”) to complement the subject.

Run-On Sentences

On the other side of the spectrum, sometimes a sentence has too much information to carry on its own; this problem is called a run-on sentence.

There are two types of run-ons, illustrated by the following examples:

• “She wanted to go to the store, but I told her not to, therefore she did not go after all.” This sentence has more than two independent clauses, so it is a run-on.
• “Marcus finished watching Captain America I think he really liked it.” While this sentence only has two independent clauses, it does not have a comma and a conjunction or a semicolon to join the two clauses.

Correcting Run-On Sentences

In order to fix a run-on, the writer must either separate the independent clauses into separate sentences or add a comma and conjunction or a semicolon.

Here are possible corrections for the previous run-on sentence examples:

• “She wanted to go to the store, but I told her no. Therefore, she did not go after all.” Now the first sentence has two independent clauses joined by a comma and conjunction, and the second sentence is just one independent clause.
• “Marcus finished watching Captain America; I think he really liked it.” Now the two independent clauses are joined with a semicolon.

Comma Splices

A common mistake that writers make when correcting run-ons or writing compound sentences is using only a comma to separate the two independent clauses. This problem is called a comma splice.

Comma splice examples:

• “Our dog chewed up the new rug, we were livid.” This sentence has two independent clauses but only has a comma to separate the two clauses.
• “Cassandra loves the local coffee shop, we got her a gift card for her birthday.” Again, this sentence has two independent clauses but only has a comma to separate the two clauses.

Correcting Comma Splices

A comma splice can be corrected by adding a conjunction after the comma or by separating the independent clauses with a semicolon or period.

• “Our dog chewed up the new rug; we were livid.” A semicolon connects the two independent clauses.
• “Cassandra loves the local coffee shop, so we got her a gift card for her birthday.” The coordinating conjunction “so” connects the independent clauses.

Lesson Summary

A complete sentence or independent clause must contain a subject, verb, and fully formed thought. An example of a complete sentence is “Charlie left their bag at school.” An incomplete sentence, or sentence fragment, is missing a subject, verb, or fully formed idea. For example, “My fence that we just put up” is incomplete. In order to fix a fragment, the writer should add the missing components. “My fence that we just put up is falling down” is a complete sentence. Dependent clauses are fragments because they contain a subject and verb but cannot stand on their own.

A run-on sentence has too many (more than two) independent clauses for it to function properly, or it is missing punctuation that joins the two independent clauses. A compound sentence with a comma in between the independent clauses is a type of run-on called a comma splice. An example of a run-on is “Julian wants to have cupcakes his dad will pick them up tomorrow.” In order to fix a run-on, the writer should separate the two independent clauses with a comma and conjunction, a semicolon, or a period. “Julian wants to have cupcakes, so his dad will pick them up tomorrow” is a possible correction using a comma and the conjunction “so.” Using just a comma without the conjunction would be a comma splice.