The question of genuine communication problems arising from structural
differences of this kind is not often seriously discussed, the assumption
generally being that non-standard speakers can "understand" standard
English presumably in the sense that in some hypothetical context-free
situation they are able to assign the same semantic structure as a standard
speaker to a given phonetic string. The reason for this assumption (which is
noted here mainly to encourage readers to consider whether they themselves
hold it) is probably the constant dissemination of spoken and written
standard English through the news media and the educational system. The
possibility that some speakers do not "understand" standard English
appears for the most part to be mooted only when their systems are so
divergent that they may, like West Indian creole-speakers in England, or
Black English-speakers in the United States, be thought of in some unsatisfactorily
specified way as not being English speakers at all (Edwards,1979; Nelson and McRoskey, 1978).