9°) Adjective clause: "Ronaldo, who joined Real from Manchester United in 2009 for £80m, said he had reached an "unbelievable" level on the pitch over the "last eight years" and wants to continue playing for another five or six seasons." (segment of interview of BBC with Cristiano Ronaldo, after he realese his film).

This sentence it's an example of adjective clause. In this example, "who" refer to people (in this case, Cristiano Ronaldo). This adjective clause is called nonidentifying or nonrestrictive, because give an additional information about the noun it refers to. The information is not necessary to identify the noun. And, in writing, a nonidentifying adjective clause is separated from the rest of the sentence by commas.