Estonian -tu

← Finnish -ton (cognate)

← Finnish -tön (mention)

← Proto-Finnic *-t'oin (inherited)

→ Estonian ohutu (affix)

→ Estonian oimetu (affix)

→ Estonian õnnetu (affix)

→ Estonian surematu (affix)

→ Estonian -matu (mention)

→ Estonian süütu (affix)

→ Estonian mõttetu (affix)

→ Estonian vältimatu (affix)

→ Estonian vahetu (affix)

→ Ingrian -toin (cognate)