comprehendHe doesn't seem to comprehend the scale of the problem.
get the pictureinformalOK. Don't say any more. I get the picture.
followIt was so complicated I couldn't follow what he was saying.
graspI think I grasped the main points of the lecture.
digestThis chapter is so difficult to digest. I'll have to read it again later.
fathomUKFor years, people have been trying to fathom the mysteries of the whale's song.
getI told him a joke, but he didn't get it.