 A comma splice should not be confused, though, with asyndeton, a literary device used for a specific effect in which coordinating conjunctions are purposely omitted.Commas are always used to set off certain adverbs at the beginning of a sentence, including "however", "in fact", "therefore", "nevertheless", "moreover", "furthermore", and "still".If these adverbs appear in the middle of a sentence, they are followed and preceded by a comma.