Question first, answer second
An oración pseudo-escindida (wh-cleft) opens with a relative clause that raises a question: Lo que quiero … After ser comes the answer, the focus. It sits at the end, where Spanish likes new information anyway. English builds it the same way: What I want is some rest.
Direct
Quiero descansar.
I want to rest.
Focus at the end
Lo que quiero es descansar.
What I want is to rest.
Nothing else matters to me right now.
The pattern
The relative word asks the question
The relative word at the start shows what is being asked about. If the focus has a preposition, it goes after ser: Donde nos conocimos fue en Sevilla.
Lo que me molesta es que no avise.
What bothers me is that he doesn't let anyone know.
lo que for things and ideas.
Quien lo organizó todo fue Ana.
The person who organised it all was Ana.
quien or el que, la que for people.
Donde mejor se come es en casa de mi abuela.
Where you eat best is at my grandmother's.
donde for places.
Cuando más trabajo tenemos es en diciembre.
When we're busiest is in December.
cuando for times.
Como mejor se aprende es hablando con gente.
The best way to learn is by talking to people.
como for manner.
Actions and announcements
When an action is the focus, Lo que hizo asks about it, and the infinitive follows ser. In conversation, Lo que pasa es que … announces an explanation or an objection.
Lo que hizo fue llamar a la policía.
What he did was call the police.
Lo que deberías hacer es hablar con ella.
What you should do is talk to her.
Lo que pasa es que no tengo tiempo.
The thing is, I don't have time.
The form of ser
Number: with a plural focus, ser is usually plural too: Lo que necesito son vacaciones. English keeps is here; Spanish does not.
Tense: ser normally takes the tense of the relative clause: Lo que quería era hablar contigo.
Reversed: the focus can also come first. That sounds conclusive, like a bottom line: Descansar es lo que quiero.
Lo que me falta son dos días más.
What I need is two more days.
Lo que quería era hablar contigo a solas.
What I wanted was to talk to you alone.
Un poco de respeto es lo que pido.
A bit of respect is what I'm asking for.
