to understand something completely充分理解;领悟
I fail to comprehend their attitude.我无法理解他们的态度。
He doesn't seem to comprehend the scale of the problem他似乎没意识到问题的严重性。
[ + that ] I don't think he fully comprehends that she won't be here to help him.我看他还没有充分意识到她是不会来这里帮他的。