While then it is certainly true that speakers with markedly different grammars are frequently able to understand each other in context, it does not seem quite justifiable to adopt uncritically the common view cited by (for example) Smith and Wilson that differences between the grammars of dialects are essentially trivial, and that potential misunderstandings can be resolved by the implementation of perceptual strategies. or by context (Smith and Wilson. 1979. p. 197). One purpose of this chapter will be to try and isolate the conditions under which differences in speakers' grammars may produce misunderstandings in natural settings; that is when the various comprehension strategies available to a speaker have failed to work and he is forced to consult his .. linguistic archive .. to assist him in interpreting utterances.