19. relative pronoun "what" (yad, n.):
 
  Sg. Du. Pl.
Nom. yat ye yani
Acc. yat ye yani
Ins. yena yabhyam yaih
Dat. yasmai yabhyam yebhyah
Abl. yasmat yabhyam yebhyah
Gen. yasya yayoh yesam
Loc. yasmin yayoh yesu
Voc. yat ye yani