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 與 worthless。invaluable 表示確實非常有用, 例如：it has a spelling checker, which is invaluable if you are dyslexic (它有一個拼寫檢查程序，對有誦讀困難的人會大有用處)。 priceless 表示非常珍貴，無法衡量其價值：priceless masterpieces by Canova and Bernini (卡諾瓦和貝爾尼尼的無價傑作)。與之相對, worthless 表示沒有什麽價值。例如：I'm afraid your shares are now worthless (恐怕你的股票現在一文不值了)。