Avoid Run-On Sentences (and comma splices)
Too often, writers have so much to say that they try to pack it all into one sentence, like a suitcase with too many clothes. In the process they write run-on sentences, not knowing when to stop or how to guide the reader. Look at this example:
I suggest we sponsor the World Cup for 2014, it will be held in Brazil, it will attract millions of viewers, our market share will increase, we will be the only sponsor in our category, it will produce a significant cost to benefit ration, we will see a big return on our investment.
In this example seven sentences, or independent clauses, have been joined by commas. (An independent clause has a subject and verb and can stand on its own.) This typical error features run-on sentences and comma splicing. The writer has joined several related thoughts (and many sentences) with commas. While some of the thoughts in the preceding sentences may be joined, the marks to use are periods and semi-colons (or a re-write of the paragraph).
This version will work better:
I suggest we sponsor the World Cup for 2014, to be held in Brazil. It will attract millions of viewers; our market share will increase; and, we will be the only sponsor in our category. In addition, the World Cup sponsorship will produce a significant cost to benefit ratio; we will see a big return on our investment.
That paragraph uses semi-colons, coordinating conjunctions, commas, and periods. You may use all of these devices, most notably a comma with a coordinating conjunction (and, but, or, nor, for, so, while and yet). For instance:
I suggest we sponsor the World Cup for 2014. It will be held in Brazil, and it will attract millions of viewer. Our market share will increase, and we will be the only sponsor in our category. The investment will produce a significant cost to benefit ration, and we will see a big return.
You may have noticed that comma splices keep the comma but not the coordinating conjunction, especially with compound sentences (two or more independent clauses). The comma and its use trick many writers. You will use a comma in lists and with other types of sentences, especially complex sentences and compound-complex sentences. For example:
If we sponsor the World Cup for 2014, to be held in Brazil, we will attract millions of viewers; our market share will increase; and, we will be the only sponsor in our category. In addition, when we sponsor the World Cup, we will see a significant cost to benefit ratio; and, we will see a big return on our investment.
Notice how these sentences use the comma and the semi-colon. So, if you want to avoid run-on sentences, use periods, commas (with coordinating conjunctions) and semi-colons. However, if you use periods, be certain not to write too many simple (and boring) sentences. Vary sentence structure. Listen to the sound of the sentences. Write to the ear and the eyes!