[2] The term refers to changes in systematic linguistic patterns of the languages in contact (phonology, prosody, syntax, morphology) rather than alterations of individual lexical items.
[2] However, as the classification of linguistic areas and language convergence depends on shared areal features, linguists must distinguish between areal features resulting from convergence and internally motivated changes resulting in chance similarities between languages.
[2] Seeking full expressive capacity in both languages, bilingual speakers identify preexisting parallels between languages and use these structures to express similar meanings, eventually leading to convergence or increasing the frequency of the similar patterns.
[5] In contrast to the limited effects of lexical borrowing, phonetic, syntactic, or morphological convergence can have greater consequences, as converging patterns can influence an entire system rather than only a handful of lexical items.
[3] When studying convergence, linguists take care to distinguish between features inherited from a language's proto-language, internally motivated changes, and diffusion from an outside source; in order to argue for language convergence, linguists try to argue for both an outside source and the mechanism that precipitated the change.