確定Although we cannot always know for certain who invented a word, we can often remember it more easily if we know the story about where it comes from. 雖然我們不能總是確定知道誰發明字, 但是假如我們知道有關字的來源的故事, 我們就能更容易地常常記住它。Would you love to know for certain how Alice likes living in California? 你很想確定知道愛麗絲喜不喜歡住在加州嗎?
確信; 弄清You must make certain to switch the light off before you leave the office. 你離開辦公室之前, 一定要把燈關上。I want to make certain when the telephone was invented. 我想弄清楚電話是什麼時候發明的。