Breakdown of Busco una esencia que sea pura y suave.
ser
to be
y
and
una
a, an (feminine)
buscar
to look for
Questions & Answers about Busco una esencia que sea pura y suave.
Why is sea used here instead of es?
The word sea is the present subjunctive form of ser. We use the subjunctive here because the speaker is looking for an essence that fits this description, but they do not have a specific one in mind yet—and they aren't even sure if it exists. If they were looking for a specific essence they already knew existed, they would use the indicative es.
Why isn't there a word for "for" after Busco?
This lesson is about combining adverbs. Why doesn't the rule for combining words like lenta y cuidadosamente apply to pura y suave?
That special rule only applies to adverbs ending in -mente (the equivalent of English "-ly") which describe how an action is performed. In this sentence, pura and suave are adjectives describing a noun (una esencia), not a verb. Therefore, they just follow normal adjective rules and both stay in their standard feminine forms to match the noun.