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imagine one of your friends is spending time with a person who you think is a bad influence. write a letter to persuade your friend to avoid this person. defend your position.

Dear (person),
I respect you and your decisions, but I think you've made a bad decision this time. I think (bad-influenced person) is a bad influence on you. They changed you and do things for you and I think that it's not fair in your position. I'm not judging or anything, I just think you should just stop spending time with (bad-influenced person). Please don't hate me, I just really think what their doing is the opposite of what you want to do, and they're kind of taking over your freedom and decisions. Like yesterday we were going to (some kind of event) at (place), but then (bad-influenced person) came along and said you were spending time with them. And i could see that you didn't want to decide between both of us, so you chose to lie. You don't lie to me, and i never lie to you. I just hope you come to your senses. Otherwise I think me and you might fight and our relationship will become a downfall. Please think about it and know your decision.
Sincerely, (you?)

Sorry that's all I have, since it all has to depend on what the person is a bad influence on.