The writer of the quotation above need have no worries about parents' underestimation of children, as far as a number of linguists are concerned. They assume that all or most language changes are due to the imperfect learning by children of the speech forms of the older generations. Others have argued that language breakdown is of special relevance to language change, since it can reveal in an accelerated form what might happen to a changing language. This chapter explores both these controversial viewpoints, looking first at the role of children in language change, then at the possible relevance of language breakdown.

The generation gap

The view that children permanently affect their language was popular at the end of the last century. ‘The chief cause of sound changes lies in the transmission of sounds to new individuals’, claimed Hermann Paul in 1880. ‘No one has ever yet been able to prevent what passes from mouth to ear from getting altered on the way’, reiterated William Dwight Whitney in 1883. ‘All the major changes in pronunciation that we have been able to investigate originate in child speech’, said Paul Passy in 1891.