Here's the answer:
“눈 깜빡할 사이에”
Watch a real native speaker say it:
Here's how it sounds in a textbook:
Fun fact: the hundreds of thousands of people learning Korean with Memrise get this phrase correct 96.06% of the time!
Fun fact: the hundreds of thousands of people learning Korean with Memrise get this phrase correct 96.06% of the time!
