sostrato | substrat | Substrat
Concept introduced by G.I. Ascoli in the 1860s, a linguistic substratum is an endemic language that, in a context of language superposition, influences an intrusive language called a superstratum. The seminal discussion by Ascoli opened the field to the concept of strata, which, with several modifications and evolutions in the studies that followed, became a crucial model for the description of multilingual areas.
For corpus-languages, substrata are quite elusive and can only be identified basing on historical information about the demographics of specific areas. They tend to emerge in corpora as low-ranking codes as opposed to the standard scribal tradition of more prestigious superstrata (cf. Anderson and Vita 2016, who present three case studies from the Semitic and Hurrian environments).
An example from the Anatolian area is represented by the presence of grammatical mistakes in the Old Assyrian corpus from Kaneš that depend on interference from the Hittite morph-syntax, e.g. the lack of proper gender marking, as in:
Šašalika (wife of Ni-ki-li-et) […] ašar libbi=šu (expected: libbi=ša) illak
“Šašalika may go where (s)he wants” (TC III 214a)
Other typical examples include the influence of Hittite syntactic patterns on the Akkadian language in texts composed in Hattuša, such as the very common reproduction of the double marked genitive with "genitive-noun" order, as in:
ša GÉMEMEŠ-šú ŠUMEŠ-ši-na (KBo 10.1 rev 11; Devecchi 2005, 52)
of his slave hands-their
"The hands of his slaves"
Note that both these examples pertain to the field of grammatical interference, as grammatical are normally the features that the superstratum (in these cases, Assyrian and Akkadian) may absorb from the substratum (in both cases, Hittite).
Andrason, A. and Vita, J. (2016). Contact Languages of the Ancient Near East – Three more Case Studies (Ugaritic-Hurrian, Hurro-Akkadian and Canaano-Akkadian). Journal of Language Contact 9, 293-334. doi: https://doi.org/10.1163/19552629-00902004. Devecchi, E. 2005. Gli annali di Hattusili I nella versione accadica. Pavia.