Abstract In Chapter 1 phonology was introduced as that part of linguistics which is concerned with pronunciation. In this chapter we shall be examining in some detail the phonology of German, but in order to do this we shall need to make a little more precise the scope and meaning of the term ‘phonology’ itself. It is useful to draw a distinction between speech as a physical activity on the one hand and speech as language on the other. Speaking involves making bodily movements and producing sounds, and these can be described in much the same way that any movements or sounds can be described, in physiological and acoustic terms. The investigation and description of speech-sounds and articulations from this point of view is called PHONETICS; it is an important and legitimate area of study in its own right, concerned with articulation and the acoustic and auditory aspects of the sounds produced, and it forms the indispensable starting-point for the linguistic study of pronunciation.1 But in considering the role of sounds in language we must go beyond the purely articulatory and acoustic facts and take into account the relationships between the sounds, and the way in which these relationships are exploited in the expression of meaning. It is this approach to which the term ‘phonology’ is applied. The terms phonetic and phonological are generally used in contrasting and complementary senses: we may speak of the ‘phonological’ as opposed to the ‘phonetic’ characteristics of speech-sounds. Just how a phonological description differs from a phonetic one will be demonstrated in the course of this chapter.