Examples: cartography card archaeology archetype monarchy legal loyal purse personal cinema kinase car carpenter hippopotamus Mesopotamia dative data date
...
English speculative
Old French speculatif (derived)
Latin speculor (derived)

English speculatively (suffix)
English nonspeculative (prefix)
English speculativeness (suffix)
English speculativity (suffix)
English antispeculative (prefix)
English unspeculative (prefix)
English overspeculative (prefix)
Danish spekulativ (link)