Examples: cartography card archaeology archetype monarchy legal loyal purse personal cinema kinase car carpenter hippopotamus Mesopotamia dative data date
...
Icelandic tví-
Proto-Germanic *twi- (inherited)
Proto-Indo-European *dwi- (inherited)
Proto-Indo-European *dwóh₁ (mention)

Icelandic tvíund (affix)
Icelandic tvíhliða (affix)
Icelandic tvíkynhneigð (affix)
Icelandic tvíkynhneigður (affix)
Icelandic tvíræður (affix)