who

used to ask about a person or people, especially when you want to know their name or identity

quién

• Who is that?
• Who are you?

Collocations who is it? · who are they?

• Who is at the door?

  ¿Quién está en la puerta?

used to introduce a relative clause that gives information about someone or something mentioned in the main clause of a sentence

quien

• the person who...
• anyone who...

Collocations the man who... · anyone who knows him

• The person who found the wallet returned it to its owner.

  La persona que encontró la cartera se lo devolvió al dueño.

used at the beginning of a sentence to introduce someone or something that is being talked about, especially when you are giving information about them

quien

• Who do you think will win?
• Who knows what will happen?

Collocations who knows... · who cares...

• Who knows if it's true?

  ¿Quién sabe si es verdad?

used in formal or written English to refer politely to someone you do not know, especially when asking for help or information

quien

• Who can I speak to about this?
• To whom am I speaking?

Collocations to whom it may concern · who is in charge here

• To whom should I address the letter?

  ¿A quién debo dirigir la carta?