Which is the easiest phone to use, for an older person?
I would go for a Nokia 220 if I were you. I personally think that Nokia feature phones are the most user friendly of all. Plus, it has a flashlight, can play audios and videos, have a FM radio, can browse websites, and have preinstalled social network apps. It only cost £29.00 from Tesco Mobile. Visit Nokia 220 page for more information.
Hope it helps! :)