Disculpe,
mi
español
no
es
muy
bueno.
¿Habla
un
poco
más
despacio,
por
favor?
dees-KOOL-peh, mee ehs-pah-NYOL noh ehs mooy BWEH-noh. AH-blah oon POH-koh mahs dehs-PAH-syoh, por fah-VOR?
Sorry, my Spanish isn't very good. Can you speak a little slower, please?
This is one of the most useful phrases you can learn. People will always appreciate the effort and gladly slow down.