If a behavior which you deem to be inappropriate or hurtful occurs, make sure that you do not react in shock or anger. Instead gently but firmly remind the person that their behavior is inappropriate. After an episode has passed do not remind the person of the incident.
Remember that the complaints criticizing your care are not deliberately done to upset you. It is the disease not the person responsible for these comments. It is not that they are unappreciative of your care but that their growing loss of independence is upsetting to them. Tell friends and family members as well to not take offense to hurtful comments made by the person you care for.
The person you care for may have difficulty understanding the emotions of others, and how they are perceived by others. Make sure you state your emotion and how you are feeling about them in conversation. For example, if they help you with the dinner, say afterwards "Thank you for helping me. That made me so happy. I am proud of you, you worked hard." Tell you friends and family to do this as well.
It may be helpful to try to change inappropriate behavior by introducing rewards for good behavior. If the person you care for attends a social event and is polite and well mannered, offer them a treat afterwards such as a favorite food or a trip to a favorite place.
Distraction techniques could assist in stopping an inappropriate behavior from continuing. Be prepared for the possibility of such a behavior to occur. You could distract through the use of music, TV, a particular food, or activity.