Definition
Used to indicate that attempting to talk to someone is pointless because they will not listen or be persuaded.
不必白費唇舌
Don't bother trying to convince him; you're just saving your breath.
別費心試圖說服他了；你只是在白費口舌。
I knew the boss wouldn't agree, so I decided to save my breath.
我知道老闆不會同意，所以我決定省省口舌。
Arguing with people who refuse to change is just saving your breath.
和那些拒絕改變的人爭論只是在白費口舌。