In historical linguistics, grammaticalization (also known as grammatization or grammaticization) is a process of language change by which words representing objects and actions (i.e. nouns and verbs) become grammatical markers (such as affixes or prepositions). Grammaticalization can involve the development of new function words from content words, rather than speakers deriving such new function words from (for example) existing bound, inflectional constructions. For example, the Old English verb willan 'to want', 'to wish' has become the Modern English auxiliary verb will, which expresses intention or simply futurity. Some concepts are often grammaticalized, others, such as evidentiality, less frequently.[1]
In explaining this process, linguistics distinguishes between two types of linguistic items:
Some linguists define grammaticalization in terms of the change whereby lexical items and constructions come in certain linguistic contexts to serve grammatical functions, and how grammatical items develop new grammatical functions.[2] Where grammaticalization takes place, nouns and verbs which carry certain lexical meaning develop over time into grammatical items such as auxiliaries, case markers, inflections, and sentence connectives.
A well-known example of grammaticalization is that of the process in which the lexical cluster let us, for example in "let us eat", is reduced to let's as in "let's you and me fight". Here, the phrase has lost its lexical meaning of "allow us" and has become an auxiliary introducing a suggestion, the pronoun 'us' reduced first to a suffix and then to an unanalyzed phoneme.
In other areas of linguistics, the term grammaticalization has taken on a much broader meaning. These other senses of the term are discussed below.
As a term referring to a research framework, 'grammaticalization' refers to that part of the study of language change that is concerned with such questions as how lexical items and constructions come in certain linguistic contexts to serve grammatical functions, or how grammatical items develop new grammatical functions.