Types of clitics
The definition quoted in the introduction may be thought of as the prototypical case. In reality, the term “clitic” has been applied to such a bewildering array of particles that it is very difficult to find a definition that will cover them all. As languages change over time, it is common for function words to undergo phonological reduction and become clitics. It is also common for clitics to become “morphologized,” that is, incorporated into their host word and re-analyzed as affixes. These changes are often gradual and may involve changes in one specific feature or property at a time, rather than sudden shifts from one category (e.g. clitic) to another (e.g. affix). So, we sometimes encounter forms that seem to be at an intermediate stage of development, with some properties that are characteristic of clitics and others that are characteristic of affixes. Nevertheless, we can identify a few basic types of clitics which are relatively common across languages.
One way of classifying clitics is by position: those which attach to the right edge of their host are called ENCLITICS, while those which attach to the left edge of their host are called PROCLITICS.1 However, a more significant basis for classification relates to their position in the sentence. Our examples thus far have involved the Amele and English auxiliaries, clitics whose position was predictable based on normal rules of syntax. The only reason for identifying these elements as clitics was their phonological attachment to an adjacent word. Zwicky (1977) refers to clitics of this type as SIMPLE CLITICS.
There are other words, however, which are identified as clitics primarily because of a special syntactic position. These forms are often unstressed, and may or may not be phonologically bound to another word. The crucial fact is that their position in the sentence cannot be predicted from the normal rules of syntax; some special rule or process is needed to account for their distribution. Zwicky refers to clitics of this type as SPECIAL CLITICS.
1. Bill Merrifield (p.c.) points out that the terms ENCLITIC and PROCLITIC are actually much older than the word CLITIC. Both of these specific terms are borrowed from late Latin, and ultimately derive from the Greek word kli̒t(os) ‘slope’; they refer to forms which must “lean on” another word. The first use of the more general term CLITIC in print was by K. L. Pike (1947:165).
