Much of what will be discussed here can be considered to pertain especially to the early years of school life. Given what has already been mentioned, it seems obvious that the first few years of school are of special importance when dealing with sociolinguistic matters. Children arrive possessing a well-formed linguistic system; this much is clear. Difficulties arise, however, because this system may not be the one encouraged and reinforced at school; it may in fact be seen as inferior and substandard. Gumperz and Hemandez- Chavez (1972) have, as noted above, supported the child's basic linguistic competence. They go on to argue further, however, that language differences .. do have a significant influence on a teacher's expectation, and hence on the learning environment" (p. 105). This is essentially the crux of the matter. Dialects which, linguistically, are just as valid systems as any other may nevertheless be viewed as invalid. Thus, having ruled out sub- stantive linguistic dialectal deficiency does not, unfortunately, also remove the social deficiencies associated with certain speech styles. This means that, for practical purposes, certain children's speech is deficient; we have simply tried so far to point out the aetiology and nature of this deficiency, and particularly to stress the power of social convention and prejudice.