in the development of articles, and in the development of personal pronouns of some languages. Some linguists, like Heine and Kuteva, stress the fact that even though obligatorification can be seen as an important process, it is not necessary for grammaticalization to take place, and it also occurs in other types of language change. Although these 'parameters of grammaticalization' are often linked to the theory, linguists such as Bybee et al. (1994) have acknowledged that independently, they are not essential to grammaticalization. In addition, most are not limited to grammaticalization but can be applied in the wider context of language change. Critics of the theory of grammaticalization have used these difficulties to claim that grammaticalization has no independent status of its own, that all processes involved can be described separately from the theory of grammaticalization. Janda, for example, wrote that "given that even writers on grammaticalization themselves freely acknowledge the involvement of several distinct processes in the larger set of phenomena, it is hard to avoid the conclusion that the notion of grammaticalization, too, tends to represent an epiphenomenal telescoping. That is, it may involve certain typical "path(way)s", but the latter seem to be built out of separate stepping-stones which can often be seen in isolation and whose individual outlines are always distinctly recognizable". Clines of grammaticality – cycles of categorial downgrading In the process of grammaticalization, an uninflected lexical word (or content word) is transformed into a grammar word (or function word). The process by which the word leaves its word class and enters another is not sudden, but occurs by a gradual series of individual shifts. The overlapping stages of grammaticalization form a chain, generally called a cline. These shifts generally follow similar patterns in different languages. Linguists do not agree on the precise definition of a cline or on its exact characteristics in given instances. It is believed that the stages on the cline do not always have a fixed position, but vary. However, Hopper and Traugott's famous pattern for the cline of grammaticalization illustrates the various stages of the form: content word → grammatical word → clitic → inflectional affix This particular cline is called "the cline of grammaticality" or the "cycle of categorial downgrading", and it is a common one. In this cline every item to the right represents a more grammatical and less lexical form than the one to its left. Examples developing a