Expanding the list of French words
Duolingo only has 1848 French word forms. While this does cover a lot of French, it leaves a lot to be learned. Perhaps they can consider pulling some translated terms from the Immersion section and pull some of those into the vocabulary section. The community can help to certify sentences that go along with words for example.
While it's hard to keep the entire tree golden, I feel like we could improve more if we were still increasing our vocabulary while becoming better at our grammar.