Is there any word(s) for a person who is poor in understanding questions.?

Question

Don't get me wrong. These people are smart, they may contribute brilliant answers & solutions.

It is just that whenever we ask a question, he/she might not be able to 'digest'/ understand the question immediately. Most of the time the person needs more time & clarification to understand a verbal question.

Answer 1

naive?

Answer 2

illeterate?? fob??  

Answer 3

Not very sharp.

Answer 4

I guess phlegmatic would work.

Answer 5

arrogant? illiterate? slow? pillock? sluggish? obtuse? boring? poor interpreter?

Answer 6

It may be the way people word the questions that confuse others or it could just be plain stupidity