Here's the answer:
“まさか！？”
(masaka!?)
Watch a real native speaker say it:
Here's how it sounds in a textbook:
Fun fact: the hundreds of thousands of people learning Japanese with Memrise get this phrase correct 95.82% of the time!
(masaka!?)
Fun fact: the hundreds of thousands of people learning Japanese with Memrise get this phrase correct 95.82% of the time!
