ARE YOU BUSY OR DO YOU NEED A BUS?
This is a pronunciation issue because when most Spanish people want to say that they are "busy" they say it like this: "bus-y".
This is not correct and will confuse a native speaker. As usual with English you can not trust the spelling of the word to tell you how to pronounce the word. In this case the correct pronunciation of the word is: "bizi".
Hope that helps!
Soy el director de Daniel Smith + Partners. Tengo más de 10 años de experiencia enseñando inglés a españoles.