In Vygotskyan sociocultural theory, private speech and collaborative dialogue are considered forms of languaging, although these terms were not used by Vygotsky himself.
Modern researchers view languaging as a key process, which allows
the shaping and organizing of higher mental processes through language.
(Lapkin, Swain & Psyllakis, 2010)
When learners explain a complex task to one another (collaborative dialogue) or when you talk aloud to yourself (private speech), thoughts are transformed by languaging into artifacts or tools which are then available for reflection.
Vygotsky believed that learning occurs in the process of putting pure thought (which he termed inner speech) into words:
Private speech is inner speech made conscious through the symbolic mediation of languaging.
(Swain, Kinnear, & Steinman, 2010)