(1) From the phonetic point of view, the importance of the tongue is that it is the organ of articulation most involved in the production of speech sounds - all the vowels and the majority of the consonants (that is, excluding those made at the lips and in the throat). Different parts of the tongue are involved in articulating these sounds, and it has proved convenient to classify sounds with reference to these areas. From front to back, it is usual to distinguish the tip (or apex), blade (or front), centre (or ‘top’), back (or dorsum) and root. The groove running down the centre of the tongue is also significant, in that several sound contrasts can be made by altering its shape. Plotting tongue movements is difficult visually or kinaesthetically, but advances in phonetic instrumentation, such as the electropalatograph, have enabled many of these movements to be displayed with accuracy.

(2) In Chomsky and Halle’s distinctive feature theory of phonology, tongue-body features constitute one of the categories set up to handle variations in place of articulation (cavity features). The placement of the body of the tongue is characterized with reference to three features, all seen as oppositions: high, low and back.