Anyone
Definition 1 of 3
Pro Tip 1/3
Unspecified Person
Used when the identity of the person is unknown or irrelevant to the context. Anyone could have taken the keys.
Pro Tip 2/3
Question Context
Commonly used in questions when asking about the presence or actions of people in general. Does anyone want dessert?
Pro Tip 3/3
Offering and Requesting
Use 'anyone' when offering or asking for something without a specific recipient in mind. Can anyone lend me a pen?