easier said than done

Từ điển tiếng Anh - Cambridge Advanced Learners Dictionary

easier said than done idiom informal
<A > said when something seems like a good idea but it would be difficult to do
• "Why don't you just ask Simon to pay?" "That's easier said than done."
Thesaurus⁺: ↑Complicated and difficult to do ↑Difficult to understand
Main entry: easy_idiom