Question: “Dear Grammar Guy, I hear people on a regular basis mixing up ‘imply’ and ‘infer.’ It drives me crazy! Could you please write a column explaining the difference? Maybe I can pin it on my cubicle wall as a sort of subtle hint.”

Answer: I think I can touch on the difference – as long as you promise not to go pinning my columns on other people’s walls. No one likes an aggressive grammar enthusiast.

“Imply” and “infer” are two sides of the same coin, which is to say that whenever an implication is present, an inference may also be drawn. First things first though: Let’s see some definitions.

Imply: “To express something in an indirect way. To suggest something without saying or showing it plainly.”

Infer: “To form an opinion from evidence. To reach a conclusion based on known facts. To guess or surmise.”

If your boss is sitting in his or her office with the door open and a smile on his/her face, that implies you might be welcome to walk in and chat. If your boss storms into his office and locks the door, however, you should probably draw the opposite conclusion.

Consider the second example. Within that sentence there is someone implying something and another person inferring something. The boss, without saying a word, is conveying with body language and other identifiable clues that he wants to be left alone. That’s an implication. The employee, on the other hand, can read the clear message – “Leave me alone” – from those nonverbal signals. That’s an inference.

The best way to keep these two words straight in your head is to remember this: To imply is to send a signal, and to infer is to receive or interpret that signal. The signaler need not be a person, either. If you see large rocks strewn across a mountaintop road, it’s safe to infer there’s been a rockslide and you may be in danger. And if you come into work next week and find this column pinned to your cubicle, you may infer that someone didn’t take my advice.