Who is eligible to teach?

I agree, anyone of those as long as you will learn or teach what you've learn.

For teaching academic lesson teachers are eligible but to teach manners, ethics, norms parents are mostly preferable . In fact we human being learn moralism from our parents , from family members and it starts before going to educational institutions.

Both and all the people you know - anyone can learn from anyone. You could learn from your child as much your child will learn from you. And anyone that is successful in some area.

All we are parents we teach our children in regard to basic knowledge we can remember, yet the change and develop methodologies increasingly's then, there are specialized teachers for different levels of education and by areas study.

Anyone that is successful with a wide range knowledge.

The primary persons to educate a child is the parents. The formative years are shared parents to children initially. Character building is developmental early on and of course external stimuli from our environment.

Both - anyone can learn from anyone and that is because a Teacher could be anyone. You could learn from your child as much your child will learn from you. Now, who is the better teacher? ... this one is a tough question... hmm .. still thinking about it...