Whose is a word we use to ask about or identify ownership or connection. When you want to know who something belongs to, you ask “Whose jacket is this?” or “Whose turn is it?” The word helps us figure out relationships between people and things.

You might hear a teacher ask, “Whose pencil is on the floor?” or a parent wonder, “Whose idea was it to build a fort in the living room?” In stories, you'll often see whose used to provide information: “The girl whose dog ran away posted signs all over the neighborhood” or “The scientist whose research solved the problem won an award.”

People sometimes confuse whose with who's. Who's is short for “who is” (as in “Who's coming to the party?”), while whose is about possession or connection. An easy test is to replace the word with “who is” in your sentence. If it doesn't make sense, you need whose. “The student who is backpack was stolen” sounds wrong because you need “The student whose backpack was stolen.”