A comma splice is a frequently committed type of grammatical error. Whenever two independent clauses are joined together with a comma, the result is a splice. In most instances, this is considered incorrect. You cannot fix a comma splice simply by removing a comma; removing the comma will merely turn the sentence into a run-on, which is an undesired result.
An independent clause is a complete sentence, containing a subject and a verb. It is possible for an independent clause to be very short. For this reason, writers sometimes graft two sentences together with a comma, because they think it will make their writing flow better. The following sentence is a comma splice: “He was walking down the street, he saw an orange.” Each of the clauses in the sentence contains a subject and verb, and can be read independently. To an experienced English reader and writer, the sentence looks awkward, and needs to be fixed. Fortunately there are a number of fixes for the comma splice.
The first is to separate the two clauses with a period. “He was walking down the street. He saw an orange.” The clauses could also be separated with a semicolon (;). A coordinating conjunction such as “and,” “but,” “of,” or “for” could be used to make a new sentence, such as: “He was walking down the street and he saw an orange.” Be aware that coordinating conjunctions create a relationship between the two clauses. Make sure to use the correct conjunction for your needs.
Another fix for a comma splice is to use a subordinating conjunction, which will turn one of the clauses into a dependent clause. Examples of subordinating conjunctions include “although,” “since,” “when,” “after,” and “while.” In this instance, a new sentence could be formed to read: “He was walking down the street, even though he saw an orange.” Finally, the comma could be replaced with a transitional word such as “nevertheless,” “consequently,” or “however.” Transitional words should be used with care. “He was walking down the street however he saw an orange” is not a correct sentence. “He was walking down the street; however, he saw an orange” is. To use a transitional word to fix a comma splice, insert a semicolon where the comma was, add the transitional word or phrase, and insert a comma after it before appending the second clause in the newly formed sentence.
A comma splice can be used for emphasis and impact, depending on who the audience for the piece is. Caesar's famous phrase veni, vidi, vici looks less emphatic when it is written “I came. I saw. I conquered.” Therefore, it is usually translated as “I came, I saw, I conquered,” in order to invoke a specific, in this case decisive, mood. Splices are also sometimes used to highlight two contrasting clauses, such as “This is a raspberry, that is a strawberry.” If you feel the need to use a deliberate comma splice, consider it carefully before taking the plunge.