What's the difference between "persuade" and "convince"?

When should "persuade" be preferred over "convince", and vice versa?

Solution 1:

Let's put some actors on a stage to help us think about the shades of meaning between these words.

Scene: Julie and Robert are discussing the difficulties of a life together. Julie's suitcase is packed and on the floor by her left hand. Their discourse has centered on emotional difficulties as well as logistical difficulties of staying together. As she picks up her suitcase and walks toward the door, Robert says:

Is there nothing I can say to convince/persuade you to stay?

If Robert uses "convince," then it seems to me that he is asking if there is a logical argument that would perhaps address the logistical difficulties in question.

If Robert uses "persuade," then it seems to have more of an appeal to Julie's emotions. (There may be a coercive component to "persuade" that is less present in "convince." Think film noir where the gangster type uses the word "persuade" as a threat, for example, "I sees dat you needs some persuading," as he smacks his fist into his palm.)

Solution 2:

When confronted with issues of word choice, I often find it helpful to consider the associations and connotations a word has in its different forms. A convincing person or argument is one that other people cannot help but agree with, whereas a persuasive person or argument is one that other people find compelling, but which leaves more room (in my mind) for the opportunity to disagree.

If you have been convinced, you have clearly and decisively changed your perspective. If you have been persuaded, then you have chosen to agree with those you previously disagreed with. In the latter case, it may not be so much that you've found an argument you agree with so much as you're indulging someone who has appealed to you, either positively or negatively.

Prefer "convince" when the change of opinion must be definite or to deemphasize the role of whomever did the convincing. Prefer "persuade" to draw attention to either the arguments used or the individuals doing the arguing, to emphasize reluctance on the part of the persuaded, or when you need the word to contain more vowels.

Solution 3:

Take a look at the following two examples:

1) He did a lot of persuading but I was not convinced.

2) He did a lot of convincing but I was not persuaded.

I may not be right but I tend to think 1) is more appropriate than 2).

In case I was right, then the difference between "persuade" and "convince" would be comparable to that between "listen to" and "hear", as shown in the following examples:

3) I tried to listen to her speech but her voice was so weak that I could hear nothing.

4) I tried to hear her speech but her voice was so weak that I could listen to nothing.

Solution 4:

How should people use 'convince' and 'persuade', according to usage guides

Many guides to style and usage address this issue. Here are some entries from guides written during the past 40 years or so, showing the historical drift of usage commentators on the subject of convince and persuade. From Harry Shaw, Dictionary of Problem Words and Expressions (1975):

convince, persuade. These words are related in meaning but do have different uses. Convince means "to satisfy the understanding of someone about the truth of a statement or situation": "Johnny convinced me by quoting exact figures." Persuade suggests winning over someone to a course of action, perhaps through an appeal to reason or emotion: "Jim persuaded the grocer to consult a lawyer."

From Roy Copperud, American Usage and Style: The Consensus (1980):

convince. The displacement of persuade by convince flouts idiom, four critics hold. One is convinced of a fact or that it is so. This is the customary usage, and the meaning of convince is create belief in. Persuade, on the other hand, means talk into or induce. Idiomatically, convince is not followed by an infinitive: "The director of the museum had convinced Brancusi to part with the sculptures for a while"; "The decree of nationalization has all but convinced Western capitalists to zip shut their billfolds"; ""We can only hope Congress can be convinced to finance the dam and the canal at the same time."In each instance, the word should be persuade, or the sentence must be recast to read convinced that he should part with, that they should zip shut, that Congress can be induced. [Rudolf] Flesch[, The ABC of Style, 1964/1966/1980] says convince with to is a new idiom, and [William & Mary Morris, The] Harper [Dictionary of Contemporary Usage, 1975] surprisingly accepts it, but neither Webster, American Heritage, nor Random House does. The consensus overwhelmingly disapproves of convince with to.

From Kenneth Wilson, The Columbia Guide to Standard American English (1993):

convince, persuade (vv.) Some conservatives still cling to what was once thought to be a semantic and grammatical distinction between these two: semantically you were to persuade somebody to act but convince somebody to that something was true, and grammatically you were to use persuade plus to and an infinitive and convince plus that and a clause. But although both conventions were strongly if confusingly and and unevenly defended until quite recently, neither describes the practices, then or now, of Standard [English] users, most of whom continue to use the two words interchangeably with of, as in Let me persuade (convince) you of the need to act {the truth of my remarks}.

From Patricia O'Conner, Woe Is I: The Grammarphobe's Guide to Better English in Plain English (1996):

convince: They convinced us that we should go. Not: They convinced us to go. With the infinitive, use persuade: They persuaded us to go.

...

convince/persuade. You convince her of something. You persuade her to do something. Convince is usually followed by of or that, and persuade is followed by to. Father convinced Bud that work would do him good, and persuaded him to get a job.

From Barabara Wallraff, Word Court (2000):

Convince, Persuade

[A reader writes:] It disturbs me to find convinced followed by an infinitive in much current writing that seems to me otherwise literate. Shouldn't it be persuaded? My thought is: one should be convinced that ...

This punctilio is so commonly overlooked that it's hard to be stern about it. Nonetheless, why not get it right? The traditional distinction is that a person who persuades you induces you to act, whereas one who convinces you changes your opinion. Thus convince to is considered incongruous.

Of course it's not easy to persuade people without at the same time convincing them. The senses of the words overlap, as perhaps this quotation from Joseph Conrad illustrates: "He who wants to persuade should put his trust not in the right argument but in the right word. The power of sound has always been greater than the power of sense." Supposing Conrad had written convince, wouldn't his idea have been equally convincing?

From Bill Bryson, Bryson's Dictionary of Troublesome Words (2002):

convince, persuade. Although often used interchangeably, the words are not quite the same. Briefly, you convince someone that he should believe but persuade him to act. It is possible to persuade a person to do something without convincing him of the correctness or necessity of doing it. A separate distinction is that persuade may be followed by an infinitive, but convince may not. Thus the following is wrong: "The Soviet Union evidently is not able to convince Cairo to accept a rapid cease-fire" (New York Times). Make it either persuade Cairo to accept" or "convince Cairo that it should accept."

From Bryan Garner, Garner's Modern American Usage, second edition (2003):

persuade; convince. In the best usage, one persuades another to do something but convinces another of something. Avoid convince to—the phrasing she convinced him to resign is traditionally viewed as less good than she persuaded him to resign.

Either convince or persuade may be used with a that-clause. Although persuade that occurs mostly in legal contexts, it does appear elsewhere— [examples omitted].

How do writers really use 'convince' and 'persuade'?

As you can see from the foregoing extracts, adherence to the traditional distinction between convince [of or that] and persuade [to] remains quite strong in a certain niche of English writing— one that happens to include a lot of copy editors.

But how widely is this distinction recognized and enforced in published writing? Bearing in mind that we're dealing with writing that has (for the most part) traveled past at least one copy editor on its road to publication, let's look at the rates of occurrence in Google Books search results from 1850 to 2005 of three sample matches: "convinced him to" versus "persuaded him to"; "convinced him of" versus "persuaded him of"; and "convinced him that" versus "persuaded him that."

First, "convinced him to" (blue line) versus "persuaded him to" (red line):

Second, "convinced him of" (blue line) versus "persuaded him of" (red line):

And third, "convinced him that" (blue line) versus "persuaded him that" (red line):

In all three charts, the dominant phrase has dropped in frequency over the past half-century, but only in the case of "convinced him to" versus "persuaded him to" dos the underdog phrase show a significant upward trend in usage over the same period. The legitimacy of Copperud's remark about "the displacement of persuade by convince" thus seems confined to the verb + to instance.

The Google Books results show that there has always been some use of the disapproved forms "convince to," "persuade of," and "persuade that," despite the best efforts of gatekeeper editors. I doubt that the vast majority of the reading public have any idea of the prescribed difference in usage between convince and persuade—and certainly the distinction that used to show the greatest degree of preference ("persuade to" versus "convince to") shows much less force in 2005 than it did 40 years before that.

Evidently, some awareness of the traditional distinction remains, and a number of usage guides published in the past two decades argue in favor of preserving the distinction. But the trend toward using the words interchangeably—or at least toward using either word with a following infinitive— seems quite strong.

As always, when a writer ignores the rules of the past, some readers—especially those taught English under the old rules—will object. It's up to each writer (and editor and publisher) to decide whether such objections are worth worrying about.