[Note: This post was updated on Aug. 20, 2021.]
Q: I’m wondering which of these is correct: “substitute A with B” or “substitute B for A”?
A: The sentences mean the same thing and both are accepted as standard English. But in our opinion, the “for” construction (as in “substitute B for A”) is preferable because it’s clearer. Here the preposition “for” means “in place of,” so you can easily tell which person or thing is being eliminated.
The “with” construction (as in “substitute A with B”), in which the verb “substitute” means “replace,” was once condemned by usage authorities but is now widely accepted. Here’s what Merriam Webster’s Dictionary of English Usage has to say:
“In its oldest and still most common transitive sense, substitute means ‘to put or use in place of another.’ ” But MW adds that “substitute has also been used since the 17th century to mean ‘take the place of; replace,’ ” and despite criticism, it’s now “being used in this sense in standard writing on both sides of the Atlantic.”
The usage guide gives published examples that illustrate both senses of the verb: “substituted asceticism for beauty” and “substitute conjecture with facts.”
The British dictionary Lexico, among others, agrees, though it acknowledges the possibility of confusion: “Traditionally, the verb substitute is followed by for and means ‘put (someone or something) in place of another,’ as in she substituted the fake vase for the real one. From the late 17th century, substitute has also been used to mean ‘replace (someone or something) with someone or something else,’ as in she substituted the real vase with the fake one.”
As Lexico comments, “This can be confusing, since the two sentences shown above mean the same thing, yet the object of the verb and the object of the preposition have swapped positions. Despite the potential confusion, the second, newer use is well established … and is now generally regarded as part of standard English.”
The Oxford English Dictionary, an etymological dictionary based on historical usage, used to regard “substitute with” as incorrect but now treats it as standard. Oxford says that “substitute” as a transitive verb—that is, one with a direct object—can be accompanied by either “for” or “with.”
In “substitute for,” the dictionary says, the preposition points to “the person or thing being replaced.” And “substitute with” means “to fill the place of (a person or thing) with a replacement.”
That last use, in which “substitute” means “replace,” Oxford notes, “has been sometimes criticized … but is now generally regarded as part of normal standard English.” So the OED now accepts a sense of “substitute” that’s long been rejected by older and more conservative usage guides.
For instance, Garner’s Modern English Usage (4th ed., 2016) maintains its earlier view that “substitute” and “replace” are not interchangeable: “You substitute something for something else … but you replace something with something else.”
However, the newest edition of Fowler’s Dictionary of Modern English Usage (2015), edited by Jeremy Butterfield, has accepted the shift.
The “substitute” entry in Fowler’s says that in its “normal uncontroversial sense” the verb is “construed with for” and means “to put (someone or something) in place of another.” But “beginning in the 17c., and running parallel to the normal sense, were transitive (often passive) uses in which the sense is ‘replace.’ ” This sense of the verb, Fowler’s concludes, “has fully re-established itself.”
Now for some etymology. The English verb is derived from the Latin substituere, which meant to choose someone to fill another’s place. When the verb entered English in the 15th century, it mean to appoint someone to a role or position in place of another.
The first citation in the OED is from the Rolls of Parliament of Henry VI (February 1447) and refers to the appointing of schoolmasters: “Suche scole maistre … [he] may in his owne parich or place remove, and an other in his place substitute and sette.”
In the mid-16th century, people began using “substitute” for things as well as people. At first, it was used with such prepositional phrases as “in the place of,” “in one’s place,” “in one’s stead,” and so on. But it began appearing with “for” in the 17th century, as shown in the OED’s earliest example:
“Xylobalsamum is the Wood of the body, or of the branch, which the Shops sometimes substituted for the liquor” (The Valley of Varietie, by Henry Peacham, 1638).
However, a few decades later, transitive uses of the verb in the sense of “replace” began appearing. And the prepositions used with this sense, when was one needed, were “by” (late 17th century) and later “with” (mid-19th).
This is Oxford’s earliest citation for the “substitute with” usage: “I carried off a rabbit from the spit, and substituted it with the cat of my old aunt” (from The Barber of Paris, an 1839 translation of a French novel published by Charles Paul de Kock in 1826).
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