How can I get my father to understand that the wife he's looking for is right beside him?

Help him look for her. By that I mean quit trying to convince him that she’s sitting right there.
“Mary is at the store dad, she’ll be home soon, let’s match these socks”.
Watch Teepa Snow on YouTube. Watch how she uses diversion. Meanwhile his wife is at work, at a PTA meeting, helping a neighbor, visiting her mother, whatever he will buy.
“Mary is spending the night with her sister, look she left your favorite pie for you”.

You can do this while you visit and maybe write some answers out for your mom to read to him when he’s agitated. The primary thing to remember is he won’t be convinced so just follow his lead.
I am very sorry for you and your mom. I know it’s hard. Watch your mom carefully as she is vulnerable with so much stress. Talk to her about respite for dad so she can get some rest.

If dad is mobile you can say..lets go look for her. And get up and walk from the living room to the kitchen, back to the living room and say...well look who's here.

I would go shopping with my Husband and he would begin to follow people thinking they were me. I often joked that I knew where he was in his brain by who he was following that day. A younger woman with long hair..me in my 20's-30's then slightly older, shorter hair and heavier...me in my 40's then grayer hair and shorter me in my 50's and if he started following gray haired old men I would know my hair was cut shorter than it should have been ;)

Kidding aside I would ask where are you going and he would say I'm looking for my wife and I would say..well I will walk with you until we find her...I would walk with him towards the exit and he would go up to the car ( I would open it with the remote) and he would leave his walker by the back door and get into the car...easy. When it became more difficult for him to get into the car I would help him then I would get in and he would look at me and smile...
It did cut some shopping trips short but that's the way some days went.
I look back and I miss those days....

While this is very sad, it's time for you and mom to come to terms with your dad's condition. He obviously can NOT understand this anymore. You're not going to make him better and make him understand anything. So, time for a deep breath and you and mom need to quickly adjust your expectations and accept the sad reality of dad's capabilities.

You gals know the reality and as long as he is safe and well cared for, which I'm sure he is, then you should feel proud and happy.

Others have suggested how to distract him, etc. He can't help and would never do something like this on purpose.

It was hard for me to play along. But that is what you need to do. Dad is not really there anymore. His mind is scrambled.

When my Dad was nearing the end of his life he got confused. Dementia? He had lots of heart problems. My daughter, RN, would go over every night to get him ready for bed. One night he fought her. She said "PopPop its me R" shecwas about 28then. He said "Your not R, she is a little girl". The Thanksgiving he died, he called her over to his bed and motioned like he was handing her something. She took it even though nothing was there. He said "this is for you". We believe he handed her a dollar like he always gave her when she was little.

I agree, you need to change your expectations. He may not bevin the time you are. There came a time when my Mom never mentioned my Dad. Then out of the clear blue, she said "W would not have liked that" She thought me and my Youngest brother were making her think she was crazy. What happened to the two between us. Go with the flow. Never argue just agree.

Several posts have talked about their LO only remembering someone as they were years ago. “You can’t be my daughter, she’s just a little girl”. Perhaps you could print out an old photo face, print it face-size, and turn it into a mask for your mother (hat elastic around the back of the head, tied onto the mask). If he recognises her, it might make your mother less sad to understand that he is loving her in his memories.

I am so sorry. My husband also did not know me. He had a tumor that involved his frontal temporal lobe of his brain causing CapGras syndrome
He would recognize my voice on the phone but in person insisted I was not his wife. It is the saddest thing ever!!!!!! Arguing will not help for a time there would be windows of time when he would recognize me but they were fleeting. He would even telephone family and friends to find out if I was with them
Good luck 🙏🏻

Great responses. Give your Mom that extra support she needs right now. Remind her that it is the disease - not her - look at the man she married - in his heart, his deep soul knows her - it is not him talking but the disease. Get out pictures of their life together to reassure her. Bless you and stay safe.

He is remembering the younger woman his wife was. Maybe put together a photo album of their years together may help. Start with photos of them together when they dated and go through major life events up to "today". Then, he can see the "girl" he loved all those years ago is the woman who is by his side today.

. There is no answer-- redirect and smile. That's all you can do. Be there for him. Enjoy him while you can. Soon he'll be gone. Enjoy him while you have him. Put your emotions aside and when he is gone you can cry and remember him as he was and not as he is. Be at peace in your soul for him and your mother. Pray she is cognizant until the day she leaves this earth to be reunited with him in Heaven.

Redirect. That is the go-to answer. It is the only answer too. Change subject or ignore him. That cannot be controlled. My mother was accusing my Dad of having affairs and he was 84 years old and sat in the recliner 4 feet from her. She was bedridden at home at that time. Dad was so agitated and upset that she was accusing him of it. She would cry and everything. Upset the whole family. She would say “ I saw you yesterday”! Well, he was there with her and he was recovering from back surgery at his age! We had to learn to REDIRECT. Only answer. Ask her a question about anything. I feel for you and family.