Difference between ‘stammer’ and ‘stutter’?

Both words are used to refer to a defect in an individual’s speech. We often meet people who have difficulty speaking; sometimes, they merely repeat the first sound or syllable of a word. They are unable to produce anything beyond that. Careful users of the language maintain that the word ‘stutter’ is used to refer to a person who has a chronic speech defect. ‘Stammering’, on the other hand, is considered temporary. All of us have ‘stammered’ sometime or the other. Human beings can stammer or stutter; machines only stutter. Speech therapists in Britain prefer to use ‘stammer’, while those in America and Canada prefer ‘stutter’. Aristotle, Aesop, Darwin, Napoleon, and Marylyn Monroe are some famous people who stuttered.

 Source: ‘Know Your English’ ( The Hindu) – July 09, 2007