non-restrictive relative clause

non-restrictive relative clause(ikke-restriktiv/unødvendig relativsetning): a  relative clause which adds extra information about the noun phrase (in which the relative clause is a postmodifier). A non-restrictive relative clause thus does not limit or restrict the reference of its antecedent in any way. Non-restrictive clauses are usually signalled in writing by commas before and after them, and in speech by tone unit boundaries on either side. E.g. The students, who love grammar, are in the middle of a lively discussion. (=All the students love grammar). Compare restrictive relative clauses.