PEN : WRITE :: pencil : sharpen ink : blue letter : compose knife : cut mistake : erase It's tempting to get excited and think "Hey, a pencil is a lot like a pen" or even to think "composing a letter is a lot like writing a letter." Yes, that's true. But your job is to treat the words as a pair. It's not the separate meanings of pencil or write that matter; it's the relationship between them! Let's take a closer look...