Communicating well with someone who has dementia is not a skill that is learned overnight - it requires patience and practice. Remember to CONNECT not to CORRECT.
Reduce distractions in the environment. For example, lowering the volume of the TV or radio.
Make eye contact and use the person's name when addressing them.
Make sure that the person is wearing a working hearing aid and/or clean glasses, if prescribed.
As some people have problems recognizing family and friends, you might want to introduce yourself and remind them who you are.
Get close enough so they can see your facial expressions and any gestures you may use.
Speak clearly at a slightly slower pace and use short and simple sentences.
Use closed-ended questions which are focused and require a simple "yes" or "no" answer.
Show respect and patience. Avoid using childish talk or any demeaning language. Don't talk about the person as if they are not there; try to include them in conversations with others.
Listen carefully to what the person is saying and observe both verbal and non-verbal communications.
Be patient and try not to interrupt the person even if you think you know what they are saying. If the person is having difficulty finding the right words, you can offer a guess as long as they appear to want some help.
Make your communication a two-way process that engages the person with dementia. Involve them in the conversation.
If you don't understand what is said, avoid making assumptions. Check back with them to see if you have understood what they mean.
Use actions as well as words. For example, if it is time to go for a walk, point to the door or bring the person's coat or sweater to illustrate what you mean. Use body movements such as pointing or demonstrating an action to help the person understand what you are saying.
Humour can bring you closer, can release tension, and is good therapy. Laughing together over mistakes or misunderstandings can help.
If the person seems sad, encourage them to express their feelings, and show your care and affection to provide reassurance.
From the Alzheimer Society of Canada.