Most sentence faults and problems with punctuation are the result of a lack of understanding of how the parts of a sentence fit together.
A quick refresher regarding parts of a sentence:
- Subjects do the action or perform the verb of a sentence.
- Objects receive the action that the subject performs.
- Verbs are the action words or linking words, and they take different tenses to show time.
English has two basic ways of combining words into groups:
- Phrases are groups of words without a subject and a verb. They are centred around nouns (in the van, by early morning).
- Clauses contain both a subject and a verb and are centred around verbs (she runs the marathon; when he saw the ruins). They have two types: independent and dependent.
All sentences are constructed from two types of clauses.
- The independent clause, which contains a subject and a verb, and expresses a complete thought:
She decided to walk to the park. (subject=she; verb=decided)
- The dependent clause, which also contains a subject and a verb but does not express a complete thought. Subordinate clauses often begin with words like since, while, although, despite, etc.:
Because it was a sunny day… (subject=it; verb=was)
Combining clauses is what sentence building is all about.
Joining a dependent clause to an independent clause requires only a comma:
Because it was a sunny day, she decided to walk to the park.
Difficulties arise when two independent clauses are joined together.
- If the writer places no punctuation between them, they become a run-on (or fused) sentence.
- If the writer places only a comma between them, they become a comma splice.
Both run-on sentences and comma splices are considered incorrect.
To join two independent clauses into one sentence, you’ll need one of the following options:
- Place a semicolon between them.
It was a sunny day; she decided to walk to the park. - Place one of the coordinating conjunctions (for, and, nor, but, or, yet, so) between them.
It was a sunny day and she decided to walk to the park. - Place one of the dependent conjunctions (although, since, it, whether, because…) before one of the independent clauses to turn it into a dependent clause; also place a comma between the clauses.
Because it was a sunny day, she decided to walk to the park.