Here's the answer:
“麻烦你说慢一点儿”
(máfán nǐ shuō màn yìdiǎn'r)
Watch a real native speaker say it:
Here's how it sounds in a textbook:
You could also say:
- má fán nǐ shuō màn yì diǎn'r
- máfánnǐshuōmànyìdiǎn'r
Fun fact: the hundreds of thousands of people learning Chinese with Memrise get this phrase correct 95.91% of the time!
