what

used to ask about a thing, situation, or idea

qué

• What is something?
• What are you doing?

Collocations what time · what day

• What's your name?

  ¿Cuál es tu nombre?

used to refer to a thing, situation, or idea that has been mentioned before or is already known about

qué, lo que

• What you need is rest.
• I don't know what to do.

Collocations what if · what about

• What I want is a cup of tea.

  Lo que quiero es una taza de té.

used to introduce a statement or opinion, especially one that you think is surprising or interesting

lo que

• What I want to say is...
• What we need now is...

• What I'm trying to say is that you're wrong.

  Lo que estoy tratando de decir es que estás equivocado.