Answer:Tybalt, Friar Laurence, Juliet
Explanation:
The first character who is to blame for the deaths of Romeo and Juliet is Romeo himself. The first reason Romeo is to blame is that he went uninvited to the Capulet party. If Romeo did not go to the party, Romeo would have never met Juliet, and Tybalt would never have known he was there
Polonius is using his daughter to spy her conversation with Hamlet. He teaches how to act naturally, how to walk and pretend that she is reading.
In that last phrase, he is saying that we humans often act in deceitful ways, for which we are to blame.
He admits that he is making a mistake, in teaching that kind of behaviour to his own daughter.
