It
is understandable why assimilation rules are found in so many of the world’s
languages. They permit greater ease of articalation. It might seem strange,
then, to learn that ew also find dissimilation rules in languages, rules in
which a segmen becomes less similar to another rather than ore similar. But
such rules do exist. They also have a ‘natural’ explanation, often from the
point of view of the hearer rather than the speaker. That is, in listening to
speech, if sounds are to similar, we may miss the contrast.
A
classic example of dissimilation occured in Latin and the results if this
process show up in modern-day English. There was a derivational suffix –alis in
Latin that wass added to nouns to from adjectives. When the suffix was added to
a noun which contained the liquid /i/ the suffix was changed to –aris, that is,
the liquid /l/ was changed to the liquid /r/. These words came into English as
adjectives ending in –al or in its dissimilated from –ar as shown in the
following examples :
As
columnar illustrates, the /l/ need not be the consonant directly preceding the
dissimilated segment.
Dissimilation
rules are quite rare, but they do occur. The African language Kikuyu has a
dissimilation rule, in which a prefix added to a verb begins with a velar fricative
if the verb begins with a stop, or with a velar stop if the verb begins with a
continuant.
