when you know someone with dementia, sometimes it's hard to find ways to spend time with them that aren't unenjoyable for them or difficult for you. so, as someone who lost their grandfather last october to dementia and spent quality time with him before that, here's some activities to try.
music. literally anything music. music activates a different part of the brain, which can be very good for people who've lost the ability to fully comprehend speech and respond. play them some of their favourite songs. sing to them. if you can play an instrument, do that. music also doesn't require any conversation, so they don't have to work as hard to keep up, and you don't have to try and keep them engaged. plus, if they're in a facility, other residents can enjoy it. music can spark emotions from memories they've lost, and i once watched my grandpa become more alert than he had been in weeks after i played my flute for him.
if possible, bring someone with you, especially if the person with dementia has aphasia. this will allow you to hold a conversation that doesn't put pressure on them to respond. don't cut them out of it, just talk like they're also a friend with you and try to ask them yes or no questions, or reference things they've done. this way they get the feeling of socialization, but they aren't under the pressure of a one-on-one conversation where they have to do back and forth.
go for a walk. we took my grandpa out and around the facility he was in, whether with a walker or a wheelchair, and it was a good exercise. you can point things out along the way and talk about them, and the great thing about dementia is that you can point out the same things every time you go for a walk and they won't call you out for it. it also provides a bit of variety. instead of staying in one place, they can experience different things, which is very important when someone is experiencing a lot of monotony. going outside can help them feel less trapped too, which is good for them since they're under constant supervision and often feel like they've lost their freedom but can't understand why.
watch a documentary or movie about one of their interests. my grandma put on a lot of nature documentaries for my grandpa when he was still living at home, and it helped keep him entertained when he lost the ability to read. people with dementia often lose the ability to engage with their interests the way they used to (reading, writing, talking about it, etc), so visual stimulation can help them engage with them again. they might fall asleep, but you can keep watching it.
play games with them. this depends on how far they've progressed and what their symptoms are, but they may still be able to play a game, albeit slowly. i recommend a card game like solitaire that you can help them with, or a jigsaw puzzle. these aren't competitive and don't have a time limit, so you can take your time and both of you can still have fun. just watch to make sure they aren't getting frustrated, and take a break if they are. activities like these can take more energy for them, and they may get frustrated at their loss of ability and difficulty with mental skills. keep it light and don't make a big deal out of it if they can't do something.
finally, just exist around them. talk with people. talk at them. read to them. eat with them. they're feeling really confused about everything, and having people around who are acting normal can help them feel a bit better. keep laughing and smiling, even when things get hard. dementia sucks for everyone involved, and you're allowed to feel bad about the whole situation, but don't put that on them. trust me, they're feeling a whole lot worse.
take it from someone who's been there: take your time with these moments. cling to what you have left. the time will come when they're gone, and these moments will be your last memories of them. grieve what you've lost, and take care of what you have left.