Usage Note: The relative pronoun which can sometimes refer to a clause or sentence, as opposed to a noun phrase: She ignored him, which proved to be unwise. They swept the council elections, which could never have happened under the old rules. More than 80 percent of the Usage Panel approved both of these examples in our 2009 survey. Sometimes which clauses of this sort are presented as separate sentences. These are technically sentence fragments, and they often pack a rhetorical punch: "I was caught for a week on the Siachen Glacier, in a giant blizzard. There is no harsher place on this earth; it belongs to no one. Which won't keep people from squabbling over it someday" (Andrea Barrett). While this example is perfectly acceptable, writers who want to avoid this use of which and adhere to the traditional rules can usually substitute this for it at the start of a new sentence, though often at the loss of some dramatic flair. · Note that which clauses that modify whole sentences can sometimes create ambiguities. The sentence It emerged that Martha made the complaint, which surprised everybody may mean either that the complaint itself was surprising or that it was surprising that Martha made it. This ambiguity may be avoided by using other constructions such as It emerged that Martha made the complaint, a revelation that surprised everybody. Remember that which is used in this way only when the clause or sentence it refers to precedes it. When the clause or sentence follows, writers must use what, particularly in formal style: Still, he has not said he will withdraw, which is more surprising. Still, what is more surprising, he has not said he will withdraw. See Usage Notes at that, what, whose.