Learn about using non-defining relative clauses.
Practice 1: defining or non-defining relative clauses.
Should these sentences have commas or not? Choose defining relative clause if you think it is correct and doesn't need commas (the information in bold is necessary). Choose non-defining relative clause if you want to add commas around the words in bold because they are extra information.
Practice 2: Who, which, that or nothing?
Choose the best way to complete these sentences. Sometimes both answers are possible, so you should choose the last option.