Q: I am having a discussion about “older” and “oldest” with several friends. We know the general rule, but the issue concerns a family with three children, and reference is made to two of them. Are they the two “older” or “oldest” children?
A: There’s disagreement among language authorities about what you refer to as the “general rule” for the use of the superlative (“-est”) and comparative (“-er”) forms in English.
Many of them believe that the “-er” form should be used when comparing two things, while the “-est” form is used when comparing three or more. However, we’d call this belief a convention, or common practice, not a rule.
We’ll have more to say later about the differing opinions among language commentators on the use of comparatives and superlatives, but let’s first consider your question
Even if you feel that “-er” should be used only with two things and “-est” with three or more, the use of either the comparative or superlative can be justified in your example.
You could choose “-est” because three children are involved. Or you could choose “-er” because two of the children, considered as a single unit, are being compared with one.
The Cambridge Grammar of the English Language makes a similar point. As the authors, Rodney Huddleston and Geoffrey K. Pullum, write, “Kim is the best of the three is equivalent to Kim is better than the other two: there is no difference in degree.”
Now let’s look at the practice of using the comparative “-er” for two things and the superlative “-est” for three or more, a subject that we’ve discussed several times on the blog.
In its definitions of the grammatical terms, the Oxford English Dictionary says a “comparative” is used “in comparing two objects,” while a “superlative” is used “in comparing a number of things.”
So when speaking of three or more things, one would have to use a superlative. But do two objects qualify as “a number of things”? If so, then it would be legitimate to use either a comparative or a superlative when speaking of two.
As we wrote on the blog in 2010, “-er” and “-est” suffixes (or versions of them) have been used to compare things since the earliest days of Old English. The practice was handed down from older Germanic languages and ultimately from ancient Indo-European.
However, the belief that a superlative shouldn’t be used for comparing two things originated much later, in the late 18th century.
Is it legitimate? Well, many great writers, including Shakespeare, Milton, Austen, Byron, Scott, Hawthorne, Thackeray, and Emerson, have used superlatives to compare two things, according to Merriam-Webster’s Dictionary of English Usage.
The usage guide says the convention requiring the comparative for two things “has a dubious basis in theory and no basis in practice, and it serves no useful communicative purpose.”
“Because it does have a fair number of devoted adherents, however, you may well want to follow it in your most dignified or elevated writing,” Merriam-Webster adds.
A devoted adherent of the convention, Garner’s Modern English Usage (4th ed.), considers the use of the superlative for two things an increasingly common “blunder.”
Bryan A. Garner, the author, ranks the usage Stage 4 (ubiquitous) on his Language Change Index. Stage 5 is fully accepted.
The Cambridge Grammar authors, Huddleston and Pullum, discuss the usage in A Student’s Introduction to English Grammar (2005):
“Usage manuals commonly say that the superlative is incorrect when the set has only two members (the tallest of the twin towers). However, the superlative is the default for set comparison, and it’s fairly common as an informal variant of the comparative with two-member sets.”
They say the use of the superlative is “relatively unlikely” with an “of” phrase (“Kim is the taller of the two”), but “sentences like Kim and Pat were the only candidates, and Kim was clearly the best are certainly grammatical.”