Translation, interpreting- often requires inventiveness to explain concepts from one language which do not exist in another, for example.
Cassandra Scott's Problem Solving Skills:
Cassandra Scott's Problem Solving Experience:
Taught someone German in the evenings as I needed extra money. He was a bit disinterested so I found a German version of a cartoon that he enjoyed on youtube and taught him using that. Held his interest and cost no money for books etc.