Whose shows possession (e.g., never trust a doctor whose plants have died).. In more formal styles we can also use it for things.
:max_bytes(150000):strip_icc()/how-to-know-whose-phone-number-it-is-4058576-3a49963affc7467b904e658733a98fb9.png "How to Know Whose Phone Number Is Calling You")
:max_bytes(150000):strip_icc()/GettyImages-1495448210-9bed6061a41643bcbdc7e853b4ec707b.jpg "How to Know Whose Phone Number Is Calling You")
Whose and who’s are homophones, meaning they sound the same but.. Who's means who is or who has.