Each word below presents an etymological puzzle. That is, your task is to figure out the etymology of each word listed below. By “figuring out the etymology”, what I have in mind is roughly figuring out what happened on the step(s) where meaning-making happened; in particular, it might be less interesting to figure out precisely from what language the term jumped to what other language, or what letter was dropped compared to some earlier initial form (though of course these could be instrumentally useful for solving the semantic puzzle), and more interesting to try to figure out a step where e.g. two words were combined into a compound.) For example, if the puzzle is “pineapple”, then a solution might involve saying that this came about by combining “pine” and “apple”, and maybe adding that the “pine” part was motivated by the resemblance with a pinecone. I recommend the wonderful https://en.wiktionary.org/ for checking answers.
doubt (also consider: kahtlema)
affiliate
maintenance
ditto
Pamplona
schizophrenia (also consider: jakomielisyys)
invent
Ferenc
Phil (if you think you have an easy answer, hover here; hover here for a hint; hover here for a second hint; hover here for a third; if the third hint was hard to make sense of, hover here for a subhint; hover here for another hint; hover here for a final hint)
intelligence
adduce