Why Should I Move My Tongue?

I have been considering the curiosity of tonal languages lately. My mother's native tongue is Sango, which has three tones. Mandarine has four. Attic Greek had, I think, three.

Tonal languages are those in which the tone of the voice has as much to do with the meaning of a word or phrase as does the pronunciation of the vowels and consonants. Thus, in the Mandarin language, the word "ba," if pronounced in a steady normally pitched voice, means the number eight. However, if it is pronounced with a falling and then a rising in the tone it becomes the verb "to hold."