Patterns of Feature Cooccurrence: The Case of Nasality

Abstract

It is widely acknowledged that certain feature combinations are more likely to occur than others. For example, the feature of nasality is much more likely to appear on segments that are voiced than on segments that are voiceless (see discussion below). Several properties of such combinatorial restrictions are important, including the following: (i) the motivation or source of such restrictions, (ii) their cross-linguistic variability, (iii) their language -internal strength, (iv) the manners in which they manifest themselves. This paper examines certain aspects of the phonology of nasal segments that bear on these issues. The paper focusses on the phenomenon of nasal opacity, where opacity is used to refer to the arresting of a process of feature propagation. When some feature (in this paper, nasality) is transmitted throughout some domain, the presence of certain opaque segments interrupts such a transmission. It is shown that in a wide range of cases involving nasality, the class of opaque segments is systematically defined. Blocking is not due to the lexical idiosyncracy of particular segments; the class of blockers is defined in terms of particular phonological features. This property raises two important issues. On the one hand, how can the possible classes of blockers be characterised in terms of their feature composition? On the other hand, by what mechanism do the opaque elements actually accomplish blocking. In the following sections, I first discuss certain cross-linguistic generalisations concerning cooccurrence restrictions involving nasality; I go on to demonstrate that the types of cooccurrence restrictions governing segmental inventories also define typical classes of opaque segments; finally, it is demonstrated that the actual mechanism for accomplishing the blocking of feature transmission involves feature cooccurrence restrictions in a central way.