Íslenskt mál og almenn málfræði - 01.01.1983, Síða 124

122 Randa Mulford
At a somewhat later stage, children come to recognize the bound
morpheme -er/-ari, in accordance with the PRINCIPLE OF PRODUC-
TIVITY. This principle predicts that children’s attention will be drawn
to an affix which is used frequently for a given meaning and that they
will then add the affix to their own repertoires of word-formation de-
vices. Once children learn such an affix, the principle of semantic
transparency predicts that they will use it at first with only one of
its meanirtgs, if it can have several, reserving other derivational devi-
ces (e.g. compounding) for the other meanings. This initially restricted
use of an affix reflects an overall tendency, also noted in other aspects
of language development, to use one form to express only one mean-
ing and to express a single meaning by the use of a single form (Slobin
1973). Among both the American and Icelandic children there was
a middle age group who used -er/-ari consistently for only one mean-
ing, usually agentive, as the semantic transparency principle (one
form-one meaning) would predict. Some of these children had a
consistent way of expressing the second meaning, while others did
not.
The third principle invoked by Clark and Hecht was the PRINCIPLE
OF CONVENTIONALITY. This principle predicts that when a child has
several word-formation devices in his productive repertoire (e.g. Verb
+man compounding, -er suffixing), he will gradually learn to use
only those devices that are conventional in the adult language. In
many cases, conventionality is tied to particular lexical items. Thus
an Icelandic child whose word-formation repertoire would allow him
to produce a variety of words for an instrument used to steer (að
stýra) such as stýrari, stýrivél, stýra or even stýri will have to learn
that in fact stýri is the only conventional adult word. More generally,
some processes are more conventional than others. For example, al-
though Verb + maður/Verb + man and Verb + vé//Verb + machine
compounds are semantically transparent, they are not conventional
forms for new agent and instrument nouns in adult Icelandic or
English. As children get older, the principle of conventionality pre-
dicts that they will rely more and more on the standard dervational
patterns of the adult language to express particular meanings. This
prediction was supported by both the English and Icelandic data.
It appears, then, that the three developmental principles invoked
by Clark and Hecht for English account equally well for the overall