I understand the technicality the words. However, in English "Where do I find it?" would be essentially the same as "Where can I find it?" So both should be acceptable, IMHO. Perhaps they're trying to force me to learn the technically correct form of the words, but I still think alternate forms should be acceptable.
> donde lo puedo en contrar
It marked me as correct, but the suggested sentence was:
> ¿Dónde lo puedo encontrar?
The thing is, it corrected me on the missing accent in "dónde" but didn't acknowledge the fact that I wrote "en contrar" instead of "encontrar."
What the rule on this? Are the two completely interchangeable?