Question: How does one do t’shuvah for speaking lashon ha’ra?

Short Answer: One who speaks lashon ha’ra and causes damage to the person being spoken about must seek forgiveness from that person, as well as following the regular t’shuvah process for sins between man and Hashem. He should also learn Torah.

Question: Is it permitted to praise your friend in front of other people?

Short Answer: It is forbidden (avak lashon ha’ra) to speak positively about your friend in front of his enemies or, even in front of friends if you excessively speak positively about him.

Question: Is it permitted to jokingly speak lashon ha’ra?

Short Answer: It is forbidden to jokingly speak lashon ha’ra, although the severity of the prohibition is debated by the poskim.

Question: Is it permitted to believe that lashon ha’ra that you told is true based on outside evidence?

Short Answer: It is permitted to believe lashon ha’ra that you know to be true based on outside evidence of which you have firsthand knowledge.