speak ill of
“悪口を言うでしょうから”
Because they’ll probably badmouth me.
— マレーナ (2000)
人の陰で悪口を言うな。
Don't talk badly about people behind their backs.
陰で彼の悪口を言うな。
Don't talk badly about him behind his back.
また彼は政府に対して以外には悪口を言う事もなかった。
Moreover, he never spoke ill of anyone except the government.
彼女はよく彼の悪口を言う。
She often badmouths him.
人前で彼の悪口を言うな。
Don't badmouth him in public.