The teacher of course brings the material to the student, typically by presenting it by making statements. If the emvironment is right and the teacher has good pedagogical skills, that should spur questions from the students.
Yes, but these statements are often posed as questions though.
> A teacher should try to avoid that and instead ask e.g. "what are you having trouble with?"
The student who is sufficiently lost answers “I’m having trouble with everything!” It takes some guided questions first to figure out exactly where the problem is.
Regardless of how badly lost some student may be, a question like "do you understand what I just said?" directed at the class in general, will almost always solicit zero responses other than everyone nodding and making approving noises. This is driven by social sense of the students, involving many contributing reasons, such as "I don't want my classmates to think I'm stupid", "I don't want my classmates to think I'm brown-nosing", and "my classmates will kill me if I make this lesson last any longer than necessary".
In my experience, this kind of thinking holds well into university years - it takes some years of adulthood for people to unlearn this pattern, and take responsibility for their own education.