Distinguishing stuttering and cluttering can be difficult. First of all, cluttering and stuttering often occur simultaneously in one patient. Secondly, the two disorders share a number of symptoms. For example, repetitions, interjections and tachylaly (speaking too fast) can be found in cluttering and stuttering. But there are also clear differences between the two disorders. For example, it looks like people who clutter are rather oblivious to the glitches in their speech, because they just talk on without worrying too much.
People who stutter, however, are painfully aware of their speech problem and would do anything to hide it. There are many more differences, by the way. Based on dozens of years of clinical experience former scientist and speech-language therapist Deso Weiss put together an overview. Also, our self-test can assist SLPs in finding out whether your client stutters or clutters.