One of the four areas is Aphasia. That is a breakdown in language, and there are a variety of breakdowns of associations due to Aphasia or language. One of them is Paraphrasia. The word "Paraphrasia", means using a word that sounds like another. People with cortical types of dementias, like Alzheimer's, do this a lot. They will say a word that sounds like another one, like "latch," instead of "match." Sometimes it might sound pretty confusing. If you know they do this a lot, you have to be very patient to try to figure out what they're trying to tell you.
Another important breakdown is having difficulty matching the sound -the spoken word - to the actual object. So, if you ask "Which dress would you like to put on today?", this is just a sound. They have no idea. If you actually pick up the dress and show it to them and say the word, they can make the connections because you're using an extra visual cue in addition to the verbal command.
Another breakdown in language is Agrammatism. If I were to make a simple request, "Touch the key with the pen," someone with Alzheimer's might just look at me and be totally confused. If I repeat the question, and if I insist, they might end up touching the pen and the key. They couldn't perform the simple task, so they really were very confused on this behaviour.
With Agrammatism, what breaks down in the brain is the relations of the words - "The," "with," "the." The client heard every single word, but they couldn't make connections among the relations between the words. Once we understand that, we can try this task again. We say, "Take the pen". There is no grammar in this request. Next say "Touch the key". They can do it. Now a behaviour that seemed confused is no longer confused because we understand the break down in the brain and what's happening, and we're using techniques to compensate and minimize the effects of their problems.