Lo
siento,
no
entiendo.
No
hablo
bien
español.
loh SYEHN-toh, noh ehn-TYEHN-doh. noh AH-bloh byehn ehs-pah-NYOHL.
I'm sorry, I don't understand. I don't speak Spanish well.
Saying 'no hablo bien español' rather than 'no hablo español' shows humility and usually makes people more willing to help.