Yes they can. However they are not worth the time and money it will take to adapt them to a DSLR. Besides they will be totally manual operation if you did. No AF and no auto aperture control. All stop down metering too.
They make good paper weights or you can turn them into a coffee mug.
I have a 45 year old Minolta MC ROKKOR-X PG 1:1.4 f=50mm lens that I use on my EOS R5. I bought a $39 adapter. The lens is manual only, but the EOS R5 displays red outlines for the edges that are in focus which makes manual focus easy. The camera has no trouble with metering. I had to set "release shutter without lens" because the lens has no electronics and the camera cannot tell that there is a lens attached. The camera has a setting for focal length that allows the IBIS to work with the manual lens.
I like how this ancient lens renders the out of focus background.
A few years ago I was going through all of our film camera gear--which included two A1's and an AE1. I spent about $35 on an FD to EF adapter so I could try them on my 6D ii (I especially was interested in keeping the 400mm and the 24mm). My experience was that it was a lot of fun to get them back out after about 25 years--maybe I got $35 worth of fun out of it--but having only manual focus and no image stabilization on the 400mm (of course) quickly made me feel better about parting with it. It made me appreciate more my husband's ability to photograph birds back then. And I really didn't see any advantage of the 24mm over the 24-105 L I had bought with my 6D ii. I was able to sell KEH all of our film camera gear.