Elder is the older of two people. Older is the older of two things or people.
Each when we think of things separately. Every when we think of things as a group.
Doing good when you are helping people. Doing well when you feel healthy.
Damage is the injury or harm of something or someone. There is no plural form. Damages is the money paid as compensation to someone for loss or injury. I was grateful that the only damage was to the roof. The amount of damages awarded was far lower...
