I think my biggest struggle is trying to explain ideas to an ELD student if they don't understand the English. My Spanish is very "street" and I comprehend a lot more than I can speak. Hablo alemán y holandés no español. This also extends to the parents. Many of my students parents are Spanish only speakers and this doesn't help with homework or communication. I feel odd using the student to translate for me.
My wife is a fluent Spanish speaker and I've been using her to improve my one semester of Spanish https://www.youtube.com/watch?v=ngRq82c8Baw