Breakdown of O horóscopo dir-te-á a verdade, não é?
dizer
to say
te
you (informal object)
a verdade
the truth
não é?
isn't it? / right? (confirms affirmative)
Questions & Answers about O horóscopo dir-te-á a verdade, não é?
How exactly is dir-te-á formed?
This is called mesoclisis, where the pronoun goes inside the verb. It happens with the future and conditional tenses. The future of dizer (to tell) for the third person is dirá. To add the pronoun te (you), you split the verb between its irregular future stem (dir-) and its future ending (-á), placing the pronoun in the middle with hyphens: dir-te-á.
Why can't we just put the pronoun at the end and say dirá-te?
In European Portuguese, the future and conditional tenses never take the pronoun at the very end. If there is no 'magnet' word (like a negative word or certain conjunctions) to pull the pronoun before the verb, it is forced into the middle. So, dirá-te is incorrect; it must be dir-te-á.
The English translation says 'won't it?', but não é? literally means 'isn't it?'. Why don't we match the future tense in the tag?
Unlike English, which changes the tag question to match the verb tense (like 'won't it?', 'didn't he?'), Portuguese keeps it simple. You can use não é? as a universal question tag for almost any statement, regardless of the tense used in the main sentence.