The arguments of a verb may leave markers on the verb about the person and number features, which is commonly called as argument indexation. We know the distinction between arguments and adjuncts is somehow vague, both for theoretical (for example, in cartographic syntax we don't need the notion of a separate Adjoin operation: adjuncts in a clause are introduced in the TP layer in the same manner arguments are introduced in the vP layer) and descriptive reasons (see Haspelmath 2014).
So can there be "adjunct indexation"? For example, can the locative NP in a language - which behaves just like commonly defined "adjuncts"- leaves a marker on the main verb? Or even the more unusual case where certain adverbs leave markers on the main verb (or adjectives leaving marker on the noun, etc.)?
References
Haspelmath, Martin. (2014). Arguments and Adjuncts as Language-Particular Syntactic Categories and as Comparative Concepts. Linguistic Discovery. 12. 10.1349/PS1.1537-0852.A.442.
