Frequency: The word is one of the 700 most common words in English.
Note: 'Who' is used as the subject or object of a verb. See entries at '~m' and '~se'.
1.
You use ~ in questions when you ask about the name or identity of a person or group of people.
Who’s there?...
Who is the least popular man around here?...
Who do you work for?...
Who do you suppose will replace her on the show?...
‘You reminded me of somebody.’—‘Who?’
QUEST
2.
You use ~ after certain words, especially verbs and adjectives, to introduce a clause where you talk about the identity of a person or a group of people.
Police have not been able to find out ~ was responsible for the forgeries...
I went over to start up a conversation, asking her ~ she knew at the party...
You know ~ these people are.
CONJ
3.
You use ~ at the beginning of a relative clause when specifying the person or group of people you are talking about or when giving more information about them.
There are those ~ eat out for a special occasion, or treat themselves...
The woman, ~ needs constant attention, is cared for by relatives...
PRON