السلام عليكم ورحمة الله وبركاته ‎احسن الله إليكم Shaykhana, what are the best approaches to deal with a situation if someone is using vulgar words or bad character towards to them. And what if it’s someone that’s close to you? ‎جزاكم الله خيرا وبارك الله فيكم

Do not answer it with the same. Be patient and repel the bad with what is better, for Allah Jalla wa ʿAlā says, the meaning of which is: Repel evil with what is better, and the one between you and him was enmity will become as a close friend. If it is someone close, advise them with good words, not harshly or with insults. If they don't listen and you want to distance yourself, you can do so.