Communication comes in many forms, especially during the different stages of dementia. If your relative is in the later stages of dementia please look at this page where there is specific information about communication which you may find helpful.
Often the first thing to go is conversations on the telephone, where the person may find it increasingly difficult to interact with callers. I realised this was happening when my mum began to make excuses when I called her: she was "just about to go out/have a bath/watch television" or she had "just woken up and was groggy".
Often the person's communication difficulty begins with them being unable to find the right words. Mum's "the thing with the nuts" - the bird feeder, and "the hot box" - the tumble drier, were two examples that she was struggling at times. It became a guessing game and resulted in much laughter when I guessed incorrectly but also led to tears, anger and frustration if I tried to play the game for too long.
Face to face communication involves so much more than speech. We need to look at the eyes of the person we're engaging, so they know we're talking to them. Our body language needs to be open and relaxed (difficult in a stressful situation, I know) and we need to watch what their bodies are saying too. I often found that, by stroking mum's hand, or giving her a hug, the reassurance took away the stress of her trying to communicate something which is clearly important at the time.
Care UK has a comprehensive guide and there is a talking toolkit from BUPA. There are other tools and charts here from Find Memory Care
Be wary of background noise; the radio, the buzz of conversation in a shop, a noisy television may make it difficult for the person you're communicating with as they may find it difficult to filter out the background interference.
Patience is the best tool, try to take the time to understand what they are saying to you and don't finish sentences off on their behalf! Speak slowly and clearly and don't invade the person's personal space and please, please, please don't talk to them as though they're a toddler! I made that terrible mistake once when I was feeling frustrated with mum and have never forgotten the look of hurt and bewilderment in her eyes.
At times, we need to think creatively; sometimes I used singing as a tool when things were difficult. I could begin with singing a question "shall we go to town or sit here with a clown?" encouraging a laugh and usually a positive response was sung back. Like all these tips though it depends on the individual - and dementia is a very individual experience; some things work for some people. Courtney told me "In the last 3 months of life, the only way grandma would stand up was to dance/sing with her. Old pub songs mostly" - a lovely way to engage!
I used questions very carefully as often people with dementia find this very difficult to handle. But I could say "it feels to me that you are feeling a bit sad today", to stimulate a response. Often tears will follow when the person can't express in words how they're feeling. In my experience, a long hug to show empathy is usually well received, though at times it can also result in some anger and frustration.
In most of our life we use questions to solicit information but as I said above, sometimes people with dementia find this difficult or even threatening. They can't process information as quickly as before so try to keep them to a minimum, with "yes" or "no" options. Asking mum what she wants for tea is difficult as there are so many choices, asking her whether she wants macaroni, and then pausing to see her reaction, or soup, if the first option receives a negative response, for example.
Another big issue: people with dementia frequently ask the same question or tell the same story, over and over again. It does become very wearing but it's important to try not to get frustrated or to finish the anecdote yourself. I didn't always get it right - we're all human after all, but I did bite my tongue and respond as best I could. It brought me up short once when, after mum had asked the same question 20 times in the course of 30 minutes, I snapped the answer back at her. She showed a moment of real insight when she commented "sometimes you think I'm just a stupid, mad old woman". I tried to keep that moment in mind when I responded to questions, it made me appreciate being in mum's shoes, and also that she was still able to understand tone of voice and body language very well.
Social situations can be difficult but sometimes people with dementia really enjoy the contact and it's essential to be supportive in the most appropriate way for the individual. It may be that by sitting with them, holding or stroking their hand, making sure the person talking to them makes eye contact, they are able to interact well. You'll need to take your cue from the person you're looking after and gently intervene if the person they're talking to asks too many questions, or doesn't listen to the answers, or - worst of all, talks down to them or asks you the question, as though they are not there. Carers need to be assertive at times and I've had to walk away from social situations by gently distracting mum or taking her to another part of the room if I've picked up signs of anxiety or tension in her body language or responses.
With thanks to @EMMACUMPSON for the picture above