system
Given the following post, respond as if you're commenting on Reddit:
human
In a classroom, (especially science, engineering and mathematics), there are students that clearly don't understand the material, yet they never ask questions, even if the teacher asks if there are any.  Why don't they ask questions?

Many times, they ultimately end up doing poorly on quizzes and exams.
gpt
Three reasons (that may overlap somewhat):

1) Not knowing what question to ask. If you don't understand something, it can be hard to formulate a question that makes sense and will increase your understanding. That's why so many questions you do hear in a classroom are garbled and make no sense, and as a consequence often the teacher fails to understand what the student is missing, or the teacher may just subtly scold them for asking a poorly-formed question.

2) Knowledge that further discussion isn't going to help anything. It may be that the teacher is not good at explaining things in different ways, or hat the concepts being taught are sufficiently complex that they can't be absorbed in a single sitting/lecture, but require further study. In this case, to ask the teacher to repeat his or herself is just wasting time that could be spent covering more material.

3) Maintenance of an image of a good, smart student. Students want to appear to be good and smart in the hopes that teachers will grade them higher. This often works, though less often in STEM fields.