Substitute and replace
Substitute does not mean Replace
by Ted Bell
There is some confusion among many people about the wordssubstitute and replace. These words are not interchangeable; they refer to the same process, but there is a difference between them. It is really quite a simple difference, a matter of the writer's or speaker's point of view.
If you substitute B for A, then you replace A by B.
It is important to use the prepositions for and by strictly in this way. If instead you use with, confusion is not just possible but very likely. Unfortunately it is not uncommon to find with used both with substitute and replace, and the result is hardly ever satisfactory. Thus you may see: "Cornflour in this recipe may be substituted with breadcrumbs" and "Breadcrumbs in this recipe may be replaced with Cornflour". In each case the meaning is far from clear. It is much better to avoid using with.
It is also a pity that B can be described as either the substitute or the replacement for A, and yet there is no corresponding word for A (unless you were to use the rather clumsy "person (or thing) replaced"). This probably compounds the original difficulty. The confusion between substitute and replace seems to be at its worst among football writers, some of whom appear to use words without really thinking about them. How else could anyone produce such a sentence as "Bloggs was substituted at the last moment"? This really is nonsense. Even by reference to the context it may be impossible to tell whether Bloggs was the player being substituted or was the player being replaced.
In any case, why should the reader have to struggle to get at the writer's meaning? It is of course one of the glories of the English language that scholars can argue about the exact meaning of a line of Shakespeare, for instance, and many accept that, with such a writer, where there are two interpretations both may be intended. But for most of us, and certainly for journalists, it is better to steer a more precise course. It is better because the object must always be communication.