中文：

保险是一种重要的金融工具，它可以帮助人们转移风险并获得一定的保障。然而，人们在购买保险时通常会关注一个问题，那就是保险什么时候返还本金。

一般来说，保险返还本金的时间和金额取决于具体的保险合同条款。一些保险合同在到期时可以返还本金，而另一些保险合同则可能只提供额外的保障而不会返还本金。在购买保险时，建议仔细阅读保险合同，了解保险的具体条款和细节，以便做出明智的决策。

如果保险合同包含返还本金条款，那么保险公司通常会在合同到期时将本金和可能的收益一起返还给投保人。一般来说，保险公司会按照合同条款的规定进行返还，但具体的返还时间和金额可能会因不同的保险公司和不同的保险产品而有所不同。

英文：

Insurance is an important financial instrument that can help people transfer risks and obtain certain protections. However, when purchasing insurance, people usually pay attention to a question: when will the insurance refund the principal?

Generally speaking, the time and amount of insurance refund depend on the specific terms of the insurance contract. Some insurance contracts may refund the principal upon expiration, while others may only provide additional protections without refunding the principal. When purchasing insurance, it is recommended to carefully read the insurance contract, understand the specific terms and details of the insurance, so as to make informed decisions.

If the insurance contract includes a refund clause for the principal, then the insurance company usually refunds the principal and possible benefits to the policyholder upon expiration of the contract. Generally, the insurance company will refund according to the provisions of the contract, but the specific time and amount of the refund may vary depending on different insurance companies and different insurance products.