It wouldn’t be too difficult to write a blog exclusively on the confusion that often arises over whether to use affect or effect in a sentence. But before taking on that challenge, let’s look at two other word pairs that are sometimes confused.

Device and Devise

Device is a noun that typically refers to a machine, or piece of equipment that has been made for some special purpose, as in “medical devices.” A device is almost always something made by human hands rather than something that occurs naturally.

Devise is a verb that means to invent or plan something that is difficult or complicated, as in devising a new treatment for patients with Stage 4 cancer.

As is often the case with other confused word pairs, device and devise have meanings that are close to each other. After all, a device may result from what someone devised in laboratory or workshop. Accordingly, it would not be unusual to use the two words in the same sentence: The scientists tried to devise a device that would make it easier to irrigate parched soil.

Collaborate and Corroborate

Collaborate  is a verb meaning “to work with another person or group in order to achieve or do something” as in to collaborate on a book about dogs or to collaborate on a Presidential campaign.

Corroborate means “to support or help prove a statement, theory, or argument by providing information or evidence,” as in “two witnesses corroborated her story” and “a theory corroborated by recent studies.”

Here, again, the meanings of these two words can intertwine so that they could plausibly be used in the same composition or even the same sentence. For example: As result of their collaboration on the experiment, the two scientists were able to corroborate the earlier findings of their mentor. Because the two lawyers collaborated in advance of the trial, the testimony of the second witness corroborated what the first witness said under oath.

Affect and Effect

Now comes the hard part, dealing with affect and effect. The problem with these two words is that one fits into the description of the other. Specifically… Affect is a verb meaning to produce an effect upon something, as in the weather affected the growth of the crops.

 Effect, on the other hand, is usually a noun meaning a change that results when something is done or happens, as in computers have had a huge effect on the way banking transactions are handled. So, if you think of affect as a verb and effect as a noun, you’ll be right most of the time.

But of course, there can be exceptions…

Effect can also be a verb, meaning to accomplish something or make something occur. For example: The lawsuit effected a change in the way employees were evaluated. There is, to be sure, a thin line between causing something to occur and producing an effect on something. Let’s tweak the previous sentence just slightly and use affect instead of effect: The lawsuit affected the way employees were evaluated. The change in meaning is very slight. Indeed, there are undoubtedly situations where one of these words could replace the other without causing any confusion. But in most writing situations, you’ll seldom go astray if you use affect as a verb and effect as a noun. If you are a student, you’ll affect your teacher in a positive way with the effect of earning a high grade.