Compound sentences are made up of two or more independent
clauses joined together; they are basically two simple sentences put together.
Compound sentences are important to writing because they provide both variety
in writing and helpful relationships between the two ideas summed up into one
sentence.
The independent clauses in a compound sentence are almost
always separated from each other in some way. Consider the following examples:
1. Many
people claim to have seen aliens, but scientists have no solid evidence to
prove aliens’ existence yet.
2. Karen
didn’t think Andrew was brave enough to skydive; therefore, she was surprised
when he jumped out of the plane with no fear at all.
3. The
pile of papers on my desk is too overwhelming; I’m taking a break and going for
a walk!
In the first example, two independent clauses are separated
by a comma and a conjunction. They are related because they both provide a point
of view on the same subject. The two clauses are contrasted by the use of the
coordinating conjunction “but”.
In the second example, the two independent clauses are
joined by a semicolon, a conjunctive adverb, and a comma. These two clauses are
related because they both describe the same person’s (Karen’s) feelings about
the subject (Andrew’s skydiving). The two clauses are contrasted by the use of
the conjunctive adverb “therefore”.
In the third example, the two independent clauses are joined
by just a semicolon. The two clauses are related because they both describe the
writer’s actions and feelings in the same scene. The two clauses are connected
by the use of a semicolon.
Finally, remember that the independent clauses in a compound
sentence should always have some relationship to each other. It is not sensible
to join random sentences together just to create a compound sentence.