Reconstruction:Proto-Slavic/-ti

• (palatalized form when the infinitive stem ends in velar consonant): *-ťi

From Proto-Balto-Slavic *-tei, from the dialectal Proto-Indo-European *-tey, the dative or locative singular of *-tis (as opposed to the regular dative *-tey-ey, with a suffix *-tey- in e-grade and the dative singular ending *-ey).

E.g. Late Proto-Slavic *dàti (“to give”) < Early Proto-Slavic *dā́ˀtei < Proto-Balto-Slavic *dṓˀtei < earlier *deh₃téy < Proto-Indo-European *dh₃téy (and not *deh₃tey-ey), nominative *déh₃tis, from the root *deh₃-.

*-ti

1. The ending of the infinitive. Not productive by itself; new verbs were created with a variety of stem-forming suffixes before the ending.

Most of modern languages, except South Slavic, Rusyn, and Ukrainian, use the shortened form *-tь (not just can be inferred from Russian, but also its lengthening effects, as in *dǫti → *dǭtь → Polish dąć.

• East Slavic:
  • Old East Slavic: -ти (-ti)
    • Old Ruthenian: -ти (-ti)
      • Belarusian: -ць (-cʹ)
      • Carpathian Rusyn: -ти (-ty)
      • Ukrainian: -ти (-ty), -ть (-tʹ)
    • Russian: -ть (-tʹ)
• South Slavic:
  • Old Church Slavonic:

    Old Cyrillic script: -ти (-ti)

    Glagolitic script: -ⱅⰹ (-ti)

  • Bulgarian: — (infinitive has been lost)
  • Macedonian: — (infinitive has been lost)
  • Serbo-Croatian:

    Cyrillic script: -ти

    Latin script: -ti

  • Slovene: -ti
• West Slavic:
  • Old Czech: -ti
    • Czech: -t; -ti (dialectal)
  • Kashubian: -c
  • Old Polish: -ć
    • Polish: -ć
  • Slovak: -ť
  • Slovincian: -c
  • Sorbian:
    • Lower Sorbian: -ś
    • Upper Sorbian: -ć

• *-iti

• Ranko Matasović (2008), Poredbenopovijesna gramatika hrvatskog jezika, Matica hrvatska: Zagreb, page 300