It doesn’t matter what language you are speaking, French, German, Chinese, as soon as you say boo in that language the person you are conversing with will just start talking away and you have no idea what they are saying. Same goes for ASL. Have no fear, just throw out this simple sign to let them know that you are just starting to learn and hopefully they will go easy on you! If they are signing to0 fast you can see a detailed description on how to ask someone to slow down their signing speed in this video
Don’t forget to use your facial expressions!