1.1 Phonetics and Phonology
Phonetics and phonology both deal with the study of human speech sounds. Phonetics is concerned with the physical side of speech, such as the actual production of speech sounds (articulatory phonetics), the acoustic properties of speech sounds (acoustic phonetics), and how sound waves are converted into linguistic information (auditory phonetics). On the other hand, phonology studies sound patterns; the organisation of sounds in a language. For example, in English, /nt/ and /dm/ can appear within or at the end of words (rent, admit), but not at the beginning. Diachronic (historical) phonology examines and constructs theories about the changes and modifications in speech sounds and sound systems over a period of time. For example, it is concerned with the process by which the English words seaand see, once pronounced with different vowel sounds (as indicated by the spelling), have come to be pronounced alike today. Naturally, there is a strong interdependency between these two areas of linguistics. So, to sum up, phonetics studies the sounds in speech while phonology studies how these sounds are used to create words in a given language.
The distinctive accents that many learners of a foreign language have while speaking the target language result from differences between the phonological and phonetic systems of their languages and those of the target language. From birth, and possibly before, until the moment we establish our own stable phonological system in our mother tongue, we learn to recognise and produce the distinctive sounds of our own language. As native speakers, we do not need to think about how to modulate our vocal tracts, or any of the other organs involved in speech, to produce sounds. This, however, might not be the case when speaking a foreign language.