It's not a virtue to speak ill of others in private.

私底下说别人坏话不是一种美德。

Don't speak ill of others.

别讲他人的坏话。

Don't speak ill of the dead.

别说死者的坏话。

She likes to speak ill of others.

她喜欢说别人的坏话。

Don't speak ill of your neighbors.

不要说邻居的坏话。