Hi Bel
My husband John has tremendous communication problems. His consultant now says (after six years) that he probably has Primary Progressive Aphasia, which may or may mot be a sub-group of AD. In fact, no-one really knows all the ins and outs of this disease, and as he says, the only was to know is by post-mortem - rather a drastic way to get a diagnosis!
On the posiitive side, the AD symptoms don't seem to show as rapid progression as with other forms.
On the negative side, as you know, it's difficult to hold a conversation, and that leads to increased isolation for the carer. It's important to keep up with outside interests and friends.
Good luck,