# Comparative or superlative to describe a quality of a member of a set of two things?

For example, 'he's the bigger of the two guards' or 'he's the biggest of the two guards'?

The comparative indicates that something is bigger/more difficult than another member. If there's only two members of the set being described, then surely both forms are equivalent?

What about when the comparative and the superlative aren't regular? e.g., 'my puzzle is the more difficult of the two' or 'my puzzle is the most difficult of the two'?

I think I'd probably use the comparative, but it seems logical that the superlative would be okay too.

• Every girl sleeping in her own bedroom can pray and give thanks every night, "I am the most beautiful girl in the room." Commented Mar 23, 2014 at 4:00
• And every Tigger can give thanks that because he's the only one, he's the one-derfullest Tigger of them all! Commented Mar 23, 2014 at 4:16

Weird. Here's a typical usage chart for XXXer / XXXest of the two with heavier/heaviest...

The same general pattern shows with older/oldest, larger/largest, etc. At some point in early C19, the superlative -est form starts to fall out of favour. Although it doesn't sound terrible to my modern ear, apparently these days we don't normally say something is the tallest of the two. The Google Books estimate in that link is totally unrealistic (there are only 27 instances, mostly old) but I'm prepared to believe there really are 44,000 instances of is the taller of the two as claimed.

What strikes me as particularly odd is that "irregular" worse/worst barely shows the effect...

I don't know why that change occurred a couple of centuries ago, but I consider it significant that worse/worst has been least affected, and better/best (also considered an irregular adjective) changed later than the strictly regular forms. My guess is that people who were less "schooled" (in logic, grammar, etc.) simply didn't bother making a special case for this particular comparative with only two candidates. Until education became more widespread, with more teachers telling more pupils to be more logical, and use the "right" word in such contexts.

But the reality is we don't apply this logic consistently. I suspect worse/worst is more resistant because it's not so obviously the pattern teachers (or our own "inner logician") rail against. But consider a context where the "only two candidates" aspect is less overt...

Kidnapper: "I'll let you go if your parents pay a ransom. Give me their phone number"
Victim: "They divorced years ago. Which parent's number do you want?"
Kidnapper: "The richest [one], dummy!"

I know the dialogue's a bit crummy, but I certainly don't think changing it to richer would help.

TL;DR: It's just "grammatical logic" telling us not to use superlatives where comparatives would suffice. But we don't tend to do this so often unless the actual words (as opposed to the semantics or "overall utterance context", for example) make it glaringly obvious.

• Ngram links have been mixed up; the older/oldest has instead larger/largest while large/largest has bigger/biggest. I'm quite curious about the older/oldest result. "I'm the eldest/oldest daughter" (if my parents have two daughters) as a statement sounds acceptable, and logical. Commented Mar 23, 2014 at 4:23
• @Mari-Lou: Dammit! I did all the searches before I started answering, but something clags up in my browser hen I use the back/forward buttons, and the links get out of step with the page displayed. Will fix... Commented Mar 23, 2014 at 4:26
• No rush :) I shall wait patiently. Commented Mar 23, 2014 at 4:26
• @Mari-Lou: Your point about being identified as the oldest daughter backs up what I'm saying. Even if the context definitely admits of "only two candidates", unless the exact words being used make this screamingly obvious, some of us are still quite prepared to use an "unnecessary" superlative. Commented Mar 23, 2014 at 4:43

"Bigger" would be natural when comparing only two, "biggest" when the set is larger. Likewise for the "more difficult/most difficult" case.

• I can't speak for any other variety of English. For all I know the answer may be different elsewhere. Hence I thought it appropriate to flag the context I was speaking from. If that isn't standard practice here, I apologize; I'm still learning this community's conventions. Commented Mar 23, 2014 at 2:57
• What @Mari-Lou said. I think it's misleading to mention AmE if you've no reason to suppose your opinion on "natural" usage is any different to anyone else's. You could always fill in "location" on your profile, or maybe wait until some Brit posts a comment saying "That's not how we speak!" (which ain't gonna happen! :) Commented Mar 23, 2014 at 4:11
• If that's the rules we're playing by, fine... Commented Mar 23, 2014 at 4:21
• It's not a "rule" just because two of us have suggested the same thing. If our reasoning make sense to you, then by all means take note. But you're in charge of your own words. Commented Mar 23, 2014 at 4:48
• Yeah, but I'd rather not get into nonproductive quibbles like this one. So... Commented Mar 23, 2014 at 4:50

Grammar books - and most people - use the comparative for two and the superlative for three or more.

The superlative would be understood for two, but it is not considered to be good written English.

• Can you cite a "grammar book" explicitly saying that the comparative (and not the superlative) should be used where only two things are involved? Or any other source backing up your assertion that the smartest twin, for example, "is not considered to be good written English"? I can believe a provincial teacher might say this, but it seems to me no credible authority would be likely to advance such a proposition. Commented Mar 27, 2014 at 13:43

the example source notwithstanding, time was when it would have been taught, correctly, that even to say, worst, as between only two entities, is grammatically incorrect. To be worst (superlative) rhetorically requires more than two points of comparison, first between a pair and then between a second pair neither of which has as yet been eliminated...hence superlative, not comparative disposition...since no more than two things can be compared at a time.