Breakdown of Este es el experto con quien trabajo en este sector.
ser
to be
en
in / on / at
trabajar
to work
con
with
Questions & Answers about Este es el experto con quien trabajo en este sector.
Why do we use quien here instead of que?
When referring to a person (like el experto) immediately after a preposition (like con), you cannot use just que. You must use quien (or phrases like el que). If there were no preposition, you would just use que, as in el experto que trabaja aquí (the expert who works here).
Can I put the preposition at the end of the clause like in English ('the expert who I work with')?
No, Spanish never allows a preposition to dangle at the end of a sentence or clause. The preposition con must stay right in front of the relative pronoun quien.
If the sentence was about multiple experts, would the word quien stay the same?
No, unlike the English word 'who', quien has a plural form. If you were talking about multiple experts, you would need to pluralize it and say con quienes trabajo.