Combining Simple Sentences to Make Compound Sentences

Combining Simple Sentences to Make Compound Sentences

When two simple sentences are combined correctly to make one longer sentence, we call that sentence a compound sentence. There are three ways to do this.

Use a Semi-Colon

See example in comma splice

Use a Coordinating Conjunction

The seven coordinating conjunctions are "and, but, or, nor, for, yet, so." Think "fanboys." Fanboys is made up of the first letter of each of the above conjunctions. For example:

The joke was funny, and it was on me.

Note the comma's place after the first simple sentence or independent clause and before the coordinating conjunction, "and". In a compound sentence, simple sentences become known as independent clauses; the two independent clauses together make up a compound sentence.

(Coordinating conjunctions can be used for many different reasons. You don't always need to put a comma before and. Just remember to do so when it is joining two independent clauses to make a compound sentence.)

Note the difference between the following two sentences:

The joke was funny, and it was on me.

The joke was funny and was on me.

The first sentence is a compound sentence with two independent clauses joined by and. The second is a simple sentence consisting of one independent clause with one subject and two verbs (or one verb used twice). For the simple sentence, a comma before "and" is unnecessary.

Use a Semi-Colon and an Adverbial Connective

Writers often confuse coordinating conjunctions with other kinds of words, such as "moreover, therefore, however, also, and furthermore," or with such phrases as "in fact, on the contrary, in addition, and as a result." 

These words and phrases can also be used to combine independent clauses and make compound sentences, but these words and phrases do not have the connecting power of coordinating conjunctions, and when you use one, you need to put a semi-colon before it. For example:

The vote was close; nevertheless, the government prevailed.

The comma which comes after "nevertheless" in the example is optional, but the semi-colon is required.

Words like these have several different names: sentence connectors, transitional words/phrases, conjunctive adverbs, adverbial connectives.

Here, adverbial connectives will be used.

Some Adverbial Connectives

Words:

accordingly            instead              then

also                      likewise             therefore

besides                 moreover           thus

consequently         nevertheless

finally                   next

first                      nonetheless

furthermore           otherwise

hence                   second

however               similarly

indeed                  still

Phrases:

all in all                  in addition                   on the contrary

as a result              in any event                on the other hand

as an illustration     in contrast                   on the whole

for example            in fact                         that is

for instance            in general                    to illustrate

for this purpose     

Summary

Methods of combining independent clauses to make compound sentences.

1. Use a semi-colon:

    This program had tremendous success; the seal populations increased significantly.

2. Use a coordinating conjunction ("fanboys") preceded by a comma:

    This program had tremendous success, for the seal population increased significantly.

3. Use an adverbial connective preceded by a semi-colon:

    This program had tremendous success; in fact, the seal population increased significantly.