Fui vs fuí

Question

In the dictado exercise Carbón (A2) there is a sentence, I was very good, Yo fui buenísima that corrects to fuí with a tilde yet I can find no source that uses a tilde with fui. Is this an error? Also the word buenísima does not appear in my New World Spanish/English dictionary, if I Google buenísima it reverse translates to muy bien but this exchanges a adjective for a adverb. What's going on here?

Answer

Hola Garrett,
I corrected the typo for "fui" with an accent. It should say "fui" with no accent. Thanks for letting us know.
"Buenísima" is a superlative. It is formed by the adjective "bueno" and the suffix -ísima which is used to say "very + adjective", e.g. "rapidísimo" (very fast), "contentísimo" (very happy)... This is why it may not show up in the dictionary. We have a lesson on this. Have a look here.
I hope this helps.
Inma