Be careful not to confuse the words invaluable, priceless and worthless. Something which is invaluable is very useful indeed. …it has a spelling checker, which is invaluable if you are dyslexic. Something which is priceless is so precious that it is difficult to give it a value. …priceless masterpieces by Canova and Bernini. In contrast, something that is worthless is of very little value. I'm afraid your shares are now worthless.

切勿混淆 invaluable, priceless 与 worthless。invaluable 表示确实非常有用, 例如：it has a spelling checker, which is invaluable if you are dyslexic (它有一个拼写检查程序，对有诵读困难的人会大有用处)。 priceless 表示非常珍贵，无法衡量其价值：priceless masterpieces by Canova and Bernini (卡诺瓦和贝尔尼尼的无价杰作)。与之相对, worthless 表示没有什么价值。例如：I'm afraid your shares are now worthless (恐怕你的股票现在一文不值了)。