|
2
|
|
2
|
Recall the previous lesson, which discussed the distribution of aspiration in English. In that lesson, it was shown that certain consonants are aspirated at the beginnings of words. However, observe the following data, remembering that a * refers to an ungrammatical form.
The data above illustrate that the consonants that are aspirated at the beginnings of words forms a subset of the English consonants.
The sounds 
, 
, 
aspirate at the beginnings of words, but consonants such as 
, 
, 
do not aspirate at the beginning of words.
Since there are rules of language that apply to only certain sets of words, it is useful to refer to such sets as being composed of a certain feature or features that are not shared by other consonants in the larger set. These subsets are known as natural classes.
Further, the features that define natural classes are known as distinctive features. The next sections will further elaborate the idea of distinctive features and introduce many of the specific features that have been proposed for human language.