Tybalt sent Romeo a letter challenging him to a duel.
Tybalt sent a challenge letter to romeo because he came to the Capulet's party uninvited.
Tybalt sends a letter to the Montague household. We learn that from Benvolio when he says to Mercutio "Tybalt, the kinsman of old Capulet, hath sent a letter to his father's house"(II, iv, 6-7) Who Benvolio means by "his father's house" is Romeo's father's house who is Montague and why Tybalt sends the letter to Montague because is to challenge Romeo in a fight.
Tybalt. He sent a letter to Montague's house challenging Romeo to a duel.
Juliet sent a letter to Montague to explain her love for Romeo and to ask for his help in ensuring their love can be accepted by their families.
Tybalt sends a letter round to the Montagues' house to challenge Romeo.
Tybalt was annoyed that he wasn't able to fight Romeo at the Capulet party because Capulet stopped him. He therefore wrote Romeo a letter challenging him to a duel. However since he delivered it to the house and Romeo hadn't been home Romeo never got the letter.
Tybalt, son of Juliet's mother's brother (whose last name was not Capulet if you work it out.)
Tybalt sends Romeo a letter containing a challenge.
because tybalt is the one to start a fight, romeo will never pick up a sword.
Tybalt. Benvolio says, "Tybalt, the kinsman to old Capulet, hath sent a letter to his father's house" , Mercutio responds "A challenge, on my life", and Benvolio then says, "Romeo will answer it." The letter is a calculated insult, intended to challenge Romeo to fight with Tybalt. Benvolio's opinion is that Romeo will "answer" the challenge, which is to say, that he will accept it and fight Tybalt. When Tybalt and Romeo arrive on the scene later Tybalt again tries to challenge Romeo by saying "Thou art a villain" (This is a pretty feeble insult but then Tybalt is not known for having any kind of brain.) You can compare the scene in Twelfth Night where Sir Andrew has been goaded into issuing a challenge to Cesario by Sir Toby. The insulting letter, which he hopes Cesario will answer, is so lame that Sir Toby decides not to send it at all.
Juliet does not know about all of those things we just saw happen in Act 3 Scene 1: the fight between Tybalt and Mercutio, the fight between Tybalt and Romeo, Tybalt's death, and Romeo's banishment.
Tybalt sent the challenge because he was angry that Romeo came to the party and that Capulet scolded Tybalt for not enduring Romeo. Tybalt was embarrassed by this and wanted revenge