I used to work with colleagues from China in contracting and I had the same experience with them. If they don't know something they have hard time saying that they don't know something or don't understand something.

Ficticious Example could be

Q: is this car red? A: it's not green. Q: yeah I know it's not green. But is it red? A: today is Thursday.

One thing I leaned it's not worth pressing forward and causing a scene. Instead it's better to use other ways of finding the information.

When guiding team members I always found it useful to have them explain back to me in their own words what they're tasked to do. It become immediately obvious if they were on the right track or not.