non-defining
adjective (also mainlyUS nondefining) uk/ˌnɒn.dɪˈfaɪ.nɪŋ/ us/ˌnɑːn.dɪˈfaɪ.nɪŋ/
(LANGUAGE)
language specialized 非限定性的
(of a clause) giving extra information about someone or something and not necessary in order to understand who or what is being referred to, or (of a pronoun) used in a clause like this
In the sentence "My younger sister, who lives in Boston, is a nurse", "who lives in Boston" is a non-defining relative clause. 在”My younger sister, who lives in Boston, is a nurse“这一句中，”who lives in Boston“ 是非限定性关系从句。
If the clause is non-defining and the antecedent non-human, you usually use which and put a comma before it, as in "He screwed the paper into a ball, which he threw in the bin." 如果这是一句非限定性（关系）从句且先行项为非人，你一般用“which"(引导从句）并在从句前加一个逗号，比如"He screwed the paper into a ball, which he threw in the bin."
In the first sentence "which" functions as a non-defining pronoun. 第一句中的“which“用作为非限定性（关系从句的）关系代词。
- More examples
- Try to expand these simple sentences into more complex ones, using non-defining clauses to add extra information.
- As you read, underline the examples of non-defining relative clauses.
- The pronoun "which" can be used in a defining and non-defining way.
Compare: defining