2. What are the general meanings of "permanent disability" and "temporary disability"? I received a lump sum from an insurance company due to a permanent disability but surprisingly recovered two years later. Can the insurance company ask me to refund part of its previous payment?
A disability, in the context of injuries, refers to the inability to carry on with one's normal activities and occupation as a result of sickness or accident.
"Permanent disability" is a disability that the insured person will not recover from. "Temporary disability" is one that the insured person will recover from.
A medical certificate must be submitted together with the claim as evidence of the insured person's condition of disability. Payment of the benefit for permanent disability may be made at one time in one lump sum or over a period of time by a series of payments.
In the above question, you have received a lump sum. Unless the payment was conditional in which you are required to refund the payment if you recover partially or wholly in future, then the insurance company cannot ask for a refund.
In usually cases, the standard terms in an insurance policy would not have a condition requiring refund where a lump sum is payable. By contrast, where the benefit is payable by installments, there could be a condition that the insured person provides proof to the insurance company from time to time of his/her continuous permanent disability. It depends on the specific terms of the policy in question.