Here's the answer:
(wǒ kéyǐ wèn nǐ yígè wèntí ma?)
Watch a real native speaker say it:
Here's how it sounds in a textbook:
You could also say:
- wǒ ké yǐ wèn nǐ yí gè wèn tí ma?
Fun fact: the hundreds of thousands of people learning Chinese with Memrise get this phrase correct 96.49% of the time!