Be patient. Maybe they do know, as someone else said. I've known some people for years and always spoke to them in Spanish, only to find out later they spoke English. Maybe your parents just want you to practice your Spanish, so they don't let you know they speak English. Knowing and using two languages has proven health benefits, too.
Another point to remember is that maybe your parents didn't have an opportunity to learn. I don't know why they went to the US, but I do know a lot of Hondurans have migrated to escape violence, poverty and other problems in Honduras. It's not easy to learn another language unless you have a lot of money. Even now where I live in Guatemala, you have to work really hard or being from a pretty rich family to have time and money to take English classes. And remember, 30 years ago there wasn't much internet access even in the US, and no smart phones with apps like Duolingo to help you learn. And when you get to a new country - depending on your circumstances - you don't have much time to devote to secondary things. You have to work long hard hours just to survive and support your family - whether they're with you in the US or back in your home country.