Breakdown of Sería mejor que tú controlaras el sonido.
ser
to be
tú
you (informal singular)
mejor
better
que
that / than
Questions & Answers about Sería mejor que tú controlaras el sonido.
Why is controlaras in the past tense if the English translation sounds like a present or future idea?
controlaras is the imperfect (past) subjunctive. Even though the action isn't necessarily in the past, Spanish grammar requires it here because the main verb sería (it would be) is in the conditional tense. Whenever a conditional verb triggers a subjunctive clause, that second verb must be in the imperfect subjunctive.
Could I say sería mejor si tú controlaras since the English translation uses "if"?
No, you must use que here. English says "It would be better if...", but Spanish handles this with an impersonal expression using que (that). The sentence literally translates to "It would be better that you controlled the sound."
Can I use controlases instead of controlaras here?
Yes, absolutely! The imperfect subjunctive has two valid sets of endings: -ra and -se. controlaras and controlases mean the exact same thing. However, in Latin America, the -ra endings are much more common in everyday speech.
Why include tú? Doesn't the ending of controlaras already tell us who is doing the action?