Breakdown of Fueron ellos los que intentaron implicar al gerente.
ser
to be
ellos
they
los
the (masculine plural)
que
that / than
Questions & Answers about Fueron ellos los que intentaron implicar al gerente.
Why is the verb fueron plural when the English translation says "It was"?
Why use this long structure instead of just saying Ellos intentaron implicar al gerente?
This structure (a cleft sentence) is used to add strong emphasis or correct a misunderstanding. By saying Fueron ellos los que..., you are shining a spotlight on the fact that they were the culprits, implicitly ruling out anyone else. It's the exact equivalent of choosing "It was them who..." over "They..." in English.
Could I say Fueron ellos quienes... instead of los que?
Yes, absolutely. When the emphasized element is a person, you can use either los que / las que or quienes as the relative pronoun. Using quienes sounds just a little bit more formal, but both are perfectly natural and interchangeable here.
Why is there an al right before gerente?