Unresolvable ??

[sasquatch]

I typed this in and my computer indicates I should use irresolvable. Is one of these the American version? help needed from expert pedants please

non-solution

I would ignore Word. Its dictionary is pretty poor. I don't think it's a UK/US issue. It's just a rather obscure word that your software doesn't know about.

They are both in my Chambers as adjectives but no idea which one to use. I was curious as it was from "how to Teach Grammar" i am using for a Celta assignment.
thanks for your replies.

Do you mean insoluble?