Suggested answer for Exercise 1

The term grammatical function identifies the part a given unit plays in the sentence: we can have subjects, objects, etc. It is not only phrases that may assume a given function but clauses as well, that is to say we can express the subject or object of a sentence with clauses, e.g. That he left surprised us – What surprised ? That he left; or Peter saw that Mary climbed up the tree – What did Peter see? That Mary climbed up the tree. A clause realising a grammatical function is not to be equated with another type of clause, relative clauses, which are used for modification, e.g.: Peter/The man that lives next door left – Who left? Peter/The man that lives next door/*The man (the original sentence contains information about the man)/*that lives next door; That Peter left surprised us – What surprised us? That Peter left/*Peter (it was not Peter, the person, it was the fact that he left that surprised us).