who, someone, somebody
誰 centers on questioning or referring to an unspecified person: asking who someone is, or talking about an unknown someone or somebody.
誰 combines 言 (speech, words) with 隹, which likely contributes the sound. The character expresses the idea of asking or speaking about an unidentified person.
The left side 言 represents words or speech, and the right side 隹 looks like a bird. Imagine asking 'who?' while pointing at a bird you can't identify: 誰 is the question word for an unknown person.
For スイ, picture a detective asking 'who?' while sipping a drink: sip -> スイ, and the question hangs in the air.
who
this or that person; anybody; many people
And Then There Were None (1938 novel by Agatha Christie)
who the heck; just who
dawn; daybreak
so-and-so
none other than; ... himself; ... herself
nice!; very good!; so witty!; that's clever
someone; somebody
a certain someone; you-know-who
whose
For Whom the Bell Tolls (1940 novel by Ernest Hemingway)
for whom
as anyone can see
everyone; anyone
a certain someone; Mr So-and-so
someone; somebody
anyone; anybody; everyone; everybody; whoever
whoever
anyone; anybody; everyone; everybody; whoever