What is the original superlative form of well?

Solution 1:

Since 'well' is a suppletive of 'good', I'll just treat 'good' and 'well' together.

What is the original superlative (and comparative) of 'good'? The current Late Modern English pattern is 'good' -> 'better' -> 'best'.The regular rule of English would suppose it is the childish-sounding over-regularized 'good' -> 'gooder' -> 'goodest'. So the question is asking what were 'better' and 'best' before? What is it that they replaced? What was the original regularity? 'good' -> 'X-er' -> 'X-est' or 'Y' -> 'Y-er' -> 'Y-est'?

Sometimes the original pattern shows up in other nearby languages. In all the related Germanic languages, Dutch, German (both West Germanic), and the North German (Danish, Norwegian, Icelandic), they -all- have the same cognate series, like good, better best but with appropriate sound changes for each branch. Swedish just -has- to be different having replaced 'gut' with 'bra' from Italian bravo' in the 17th c.

This means that all the Germanic languages have the same question, what corresponds to 'good' in the comparative/superlative? If you try to go further back, to Proto-Indo-European, none of the other branches share a cognate with 'good' or 'better' - all have roots entirely different from Proto-Germanic (e.g. Proto-Italic bonum, melior, optimum; Proto-Slavic dobro, lepshi/bolji - .

So there doesn't seem to be any word that was replaced. Except there is some slight evidence that 'good' itself was the lexical item that was replaced, not the less frequent comparative/superlative.

There is a Proto-Germanic word 'bat' meaning advantage or improvement.  Its comparative form was 'batizon' and its superlative was 'batistaz' which is uncontroversially the the etymon of 'better' and 'best'. The simple adjective 'bat' was replaced by 'good'. In other words, while it is commonly understood that the 'bet-' root suppleted some derivation of 'good', it seems more likely rather that 'good' suppleted the regular paradigm entry of 'bat'.

The table for the this is in Wikipedia's article on suppletion - the paradigms of good better best. There they give examples of 'good' in all the European families.

In many Germanic languages, it turns out that there may be a possible remnant of 'bat'. In English, it is surmised that the word 'boot' as in (etymonline, n 2](https://www.etymonline.com/word/boot)

I got a dozen bagels and the baker put in another one to boot.

The answer to the title question is that there really is no original comparative/superlative that is known, but that there is more likely an original (ie older) version of 'good' that makes the paradigm regular, and that word is cognate with 'to boot' meaning 'extra'.

@tchrist pointed out to me that in Old English and surviving into Middle English (and in other Germanics), there was an alternative synonymous paradigm based on 'sel-'.