Tongue Twisters are a great way of helping children and foreigners pronounce difficult sounds. Speech therapists have used them for years to help children overcome speech difficulties and they are also a very helpful tool in developing the ear and tongue of foreign language students.
Many of the classic tongue twisters drill sounds like 'th', 'ea', 'i' and 'sh' which are all particularly difficult for speakers of romance languages like Portuguese, Spanish, French and Italian to master. The ability to distinguish these sounds in speech and to pronounce them correctly in English can mean the difference between being understood and being mocked. Because each these rhymes repeat a small number of sounds in different patterns they are an excellent way of varying other pronunciation drills, and because they are usually challenging and fun, they are motivating for the students.
You can find collections of tongue twisters on the web and you probably remember a few from your own youth, but Dr. Seuss' classic, 'Fox in Sox' is another source of these rhymes which will really challenge your students and entertain them. The old 'she sells sea shells' rhyme is excellent because it practises both the tricky 'sh' sound, and short and long 'e's so that the students is forced to listen carefully and notice the different positions of lips, teeth and tongue while making the sounds. Even native English speakers can benefit from these exercises because we tend to get sloppy in our use of our own language. As the linguist in "My Fair Lady" said commenting on Eliza's perfect pronunciation, 'whereas others are instructed in their native language English people aren't!' The phrase 'Unique New York', repeated at increasing speed is enough to cause the nimblest tongue and brain to stumble.
Five to ten minutes during the lesson spent reviewing recently learned tongue twisters and practicing new ones will soon lead to audible progress in pronunciation and it can easily be turned into a game or a competition as well as a drill. When teaching new rhymes the teacher should say them slowly and encourage students to pay careful attention to the sound they are making and position of mouth and tongue while making it, and only speed up when the students can say it accurately. Speed is not the goal, accuracy is. Practicing the Tongue Twisters should be part of the student's regular homework, and they should be encouraged to work on speed only after they have mastered saying the rhyme properly without stumbling.
Students of all ages enjoy the challenges of this exercise, even when the rhymes themselves are nonsense. The teacher should make it clear that the purpose of learning them is to emphasize the sounds rather than the sense and not spend too much time explaining their meaning, although some of them can be used for a quick drill in various aspects of grammar or vocabulary.
As well as reciting them chorally you can turn the tongue twisters into speed competition or you can play games in which each student says one or more words before another student continues, either taking turns around a circle or throwing a bean bag across to the next one, and many others. This kind of exercise can provide either a break in the midst of longer lessons, or a good opening or closing exercise for the lesson and helps you vary the structure of the lesson and hold your students' interest.