Alastair’s Place

Software development, Cocoa, Objective-C, life. Stuff like that.

“affect”, “effect”, “infer” and “imply”

Over the past few months I’ve noticed a number of people misusing all four of these words. Since the dictionary definition is unlikely to be helpful in such cases, I thought I’d give some examples of correct usage in the hope that anyone who is confused will find this post and get it right.

Let’s deal with affect versus effect first:

Wrong: The position of the switch effects the light output of the lamp.
Right: The position of the switch affects the light output of the lamp.

Wrong: The lamp is effected by the position of the switch.
Right: The lamp is affected by the position of the switch.

Wrong: To effect the lamp, one can push the switch.
Right: To affect the lamp, one can push the switch.

Wrong: To affect a change in the lamp, one can push the switch.
Right: To effect a change in the lamp, one can push the switch.

Wrong: The affect of the switch is to change the light output of the lamp.
Right: The effect of the switch is to change the light output of the lamp.

Wrong: A change in the lamp may be affected by pushing the switch.
Right: A change in the lamp may be effected by pushing the switch.

Now infer versus imply (this is a little more complicated :-)):

Wrong: Mr. Smith implied from the e-mail that Mr. Jones did not like cats.
Right: Mr. Smith inferred from the e-mail that Mr. Jones did not like cats.

Wrong: “From the e-mail,” said Mr. Smith, “we must imply that Mr. Jones does not like cats.”
Right: “From the e-mail,” said Mr. Smith, “we must infer that Mr. Jones does not like cats.”

Wrong: The e-mail inferred that Mr. Jones did not like cats.
Right: The e-mail implied that Mr. Jones did not like cats.

Wrong: The inference of the e-mail was that Mr. Jones did not like cats.
Right: The implication of the e-mail was that Mr. Jones did not like cats.

Wrong: In the e-mail, Mr. Jones inferred that he did not like cats.1
Right: In the e-mail, Mr. Jones implied that he did not like cats.

Wrong: From the e-mail, Mr. Smith implied that Mr. Jones did not like cats.
Right: From the e-mail, Mr. Smith inferred that Mr. Jones did not like cats.

Right: “Are you inferring that I don’t like cats?” said Mr. Jones.2
But more likely: “Are you implying that I don’t like cats?” said Mr. Jones.

In case it’s still not clear:

  • You can effect a change on something. In which case you have affected it.
  • You can have an effect on something. In which case it is affected by you.
  • You can imply something. In which case others can infer something from your remark.
  • You can infer something from someone else’s remarks. In which case they may have implied it. (Note the word “may” here; inference is the act of reading between the lines, so it is possible to read something the author did not intend.)

Finally, you can read dictionary definitions of affect, effect, infer3 and imply.

Why does all this matter? Well, for one thing, if your English is sloppy and you are arguing a case for something, your argument may look less persuasive—indeed, less rational—than the counter argument. There is no reason to suppose that those arguing the opposite position will be sloppy in their use of English.

Poor use of English shows a lack of care and a lack of pride in your writing, not to mention a lack of respect for the reader—if you don’t care sufficiently about your writing, why should the reader bother reading it? Why did you bother to write it in the first place?

When written well, English is a wonderful, expressive language; irregular and awkward it may be, but it has a beauty both of sound and of meaning. Careless mistakes mar that beauty and reduce the enjoyment of the reader.

1 Unless you mean that Mr. Jones is being written about in an e-mail and in that e-mail he inferred that some other person—Mr. Smith, perhaps—did not like cats, in which case it would be right. Isn’t English wonderful? :-)

2 In the first case, Mr. Jones is asking if the other party has come to the conclusion that he—Mr. Jones—does not like cats. In the second, Mr. Jones is asking if the other party is stating indirectly that Mr. Jones does not like cat. The two have different meanings, but they are both correct. You are more likely to want the second meaning.

3 The author of the Usage Note from the Random House Unabridged Dictionary in my view misunderstands the sentence it quotes, “The next speaker criticized the proposal, inferring that it was made solely to embarrass the government.

There is nothing wrong with the sentence at all; it is the speaker who infers that the proposal was made to embarrass the government. It is not the proposal that does the inferring here, and so their claim that this sentence lends credence to the misuse of the word “infer” is incorrect.