←
Proto-Indo-European *dwóh₁ (derived)
→
Esperanto dua (mention)
→
Esperanto duuma (suffix)
→
Esperanto duona (suffix)
→
Esperanto dudek (compound)
→
Esperanto duono (affix)
→
Esperanto duope (affix)
→
Esperanto duopo (affix)
→
Esperanto duopa (affix)