I have come across this phenomenon a few times – people who can speak English very well indeed and are capable of using a wide variety of natural expressions, but, for some reason they are not always able to understand certain aspects of the content of more complex conversations. These people give the impression that they have followed and absorbed every single word, but then they say something which indicates that they have not understood a previous section of the discourse and this gives them away. Yours truly also has this problem with complex conversations in Italian.
The question is: How do you raise the level of comprehension in people who already seem to be at a very high level? And: What exactly is causing them to miss certain parts of a discourse? Personally, I think I may still have a problem with the speed of a conversation and my knowledge of Italian vocabulary is still not as high is it needs to be. A possible solution may be to do a course with a teacher focusing purely on the development of comprehension skills. It may be a little difficult to find really challenging comprehension materials, although original language films could be used. It would however be necessary to ensure that the individual concerned is not finding the material too easy, in which case something more challenging would be required.
A certain amount of analysis would be required on the part of the teacher to try to understand the root of the problems. Lack of vocabulary or a lack of knowledge of complex syntax employing structures which are unfamiliar to a student may be part of the problem, but the reason may simply be down to the pace of the discourse and the inability of a student to ‘hear’ key information. Searching, detailed comprehension activities may be able to resolve the problem, as may requiring a student to repeat the exact words or explaining what has been heard in as precise as way as possible. The teacher should ‘dig’ until he or she is convinced that the student has really understood all the details.
A few sessions like this may just be able to raise an already high comprehension level even higher. As for me, I think I need to listen to Italian radio more often and attempt to find a channel which contains chat shows which cover issues that are more complex than everyday chit-chat.