非限制性定语从句用于对所修饰的成分进行进一步的说明，通常与主句之间用逗号隔开，即使去掉了从句，主句的意思仍然完整。以下是一些非限制性定语从句修饰事情的例句：

which引导的非限制性定语从句

She heard a terrible noise, which brought her heart into her mouth.

David studies hard and is ready to help others, which is what his parents expect.

who引导的非限制性定语从句

The note was left by Jim, who was here a moment ago.

She introduced me to her husband, whom I hadn't met before.

whose引导的非限制性定语从句

This is George, whose class you will be taking.

The boy, whose father is an engineer, studies very hard.

as引导的非限制性定语从句

Above the trees are the mountains, whose magnificence the river faithfully reflects on the surface.

综合例句

Our guide, who was a French Canadian, was an excellent cook.

Mr. Smith, from whom I have learned a lot, is a famous scientist.

这些例句展示了非限制性定语从句在不同情况下的应用，它们能够提供关于主句中名词或代词的额外信息，同时保持句子的完整性和流畅性。