To my understanding, the meaning of the verb changes depending on whether it
is followed by "with" or "for."

"Substitute A for B" means to remove B and replace it with A.

"Substitute A with B" means to remove A and replace it with B.

Antony Davies

-----Original Message-----
From: Coffin, Donald [mailto:dcoffin@iun.edu]
Sent: Monday, February 06, 2006 11:24 AM
To: Teaching Econ Discussion List (E-mail)
Subject: "Substitute for" vs. "Substitute with"

I've run into a use of language in the last week that I guess I have never
heard before, and wondered how widespread it is.

A student asked me if I could use language other than "substitute A for B,"
because he could not figure out whether that meant "substitute A with B" or
"substitute B with A."

I think "substitute B with A" means "replace B with A," but I'm not sure.

Has anyone else run into this? If so, what do you do?