Breakdown of Fui yo quien mencionó la cifra verdadera.
yo
I
ser
to be
quien
whom / who (relative singular)
verdadero
true (real, authentic)
Questions & Answers about Fui yo quien mencionó la cifra verdadera.
Why does the sentence start with Fui (I was) instead of Fue (It was)?
In English, we use the impersonal "It was..." (as in "It was me"). However, in Spanish cleft sentences, the verb ser (to be) must match the person you are emphasizing. Since the emphasized person is yo (I), you must use the "yo" form in the past tense: Fui yo. If you were emphasizing "you," it would be Fuiste tú.
Why is the verb mencionó (he/she mentioned) instead of mencioné (I mentioned) if it was me who did it?
This is a tricky rule! Grammatically, the relative pronoun quien acts as a third-person singular subject. So, the verb that follows it normally takes the third-person form (mencionó), even though it refers back to yo. Note: You will also hear native speakers say Fui yo quien mencioné, which is completely valid and accepted, but the third-person mencionó is standard and very common.
Could I use el que or la que instead of quien in this sentence?
Why is the adjective placed after the noun in la cifra verdadera?