My Suggestions

nĩyo

cop.

  1. it is it; that is it (copula, class 9)
  2. Emphatic identification: "nĩ" (is) + "yo" (it, class 9)

Example: "Mbaũ ya gatatũ nĩyo ĩratũheire ũhotani" — The third plan is what gave us opportunity.