Came here to post the same link. English adjective order is one of those things that we're never taught as speakers of English as a first language, but I'd imagine it's taught to those learning it as a second language.
As a native English speaker I was never taught a rule that explains why I would say hotter or wrigglier or redder or wildest or shiniest, but more emphatic, more open, most excellent or most orange. I'd always assumed adjective -er and -est suffixes were just irregular, with no pattern to them at all.
But it turns out there's basically a simple rule - if it ends in '-y' or has only one syllable, you suffix it; otherwise you use the 'more' or 'most' form. It's remarkably solid as a rule, and even when I come up with a word that sounds sort of right to my ear that doesn't follow the rule - like, for example, I can kind of see 'wickedest' as being a valid form - it turns out that if I think about it, it probably doesn't sound right after all, and I would probably prefer 'most wicked'.
An example that strongly goes against the rule:
simpler (3185) / more simple (153)
simplest (2191) / most simple (87)
But that would be true even if I were in the minority. The corpus is just going to reflect usage, and my usage is as valid as any other, so... while it provides some sort of peer validation, it doesn't answer the question of whether one form or another is 'more correct', only whether one is 'more common'. Or commoner, maybe. No, I'm going to stick with more common.
Since -ly is an adverbizing suffix, most anything ending in -ly could also end in -lier or -liest. A dual-purpose word might generate ambiguity when using -er, because -er is also used to transform a noun or verb into an associated noun, much like -ing changes a verb.
"Opener" could be an adjective meaning less enclosed, or it could be a person or device that opens things.
Hot may become hotter and hottest, but heated can only become more heated, because it is already heat and -ed, and the suffixes won't combine. Old becomes older and oldest, but aged only becomes more aged. Red -> redder -> reddest; rouged -> more rouged.
Likewise, the -tic suffix does not combine. Emphatic is already an adjective form of emphasis. The -er and -est suffixes tend to attach more easily to a word that was originally a modifier rather than a noun or verb, because only a few suffixes that modify part of speech combine. I wonder if it would be better to be "most emphatic" or "most emphasized"?
The rules are complicated because English grabs vocabulary from so many other languages, and the words with germanic, romance, greek, or other etymologies don't always play well by the same rules.
Native English speakers are somehow able to apply etymologically consistent alteration rules to words based on the qualities of their sound rather than by their actual source language. That's how we got "cherry". The French word was "cerise", which was imported as "cherries". Obviously, by English grammar, a word ending in the /s/ or /z/ sound is a plural. So you chop off the /z/ to get the singular "cherry". English has sort of a Procrustean Bed approach to word acquisition. If it don't fit, we makes it fit.
You're right that '-ed' suffixes prevent '-er'/'-est' being appended even if they don't add a second syllable to their root, though in most cases '-ed' makes a word multisyllabic so forces it down the 'most' route. 'bored' or, as you say, 'rouged' are monosyllabic exceptions, though. And that's in spite of there being no awkward sound created - you could certainly say 'boreder' (it's pronounced just like 'border' or 'boarder'), but it's not a word. English is weird.
But with 'open', I don't see your point. It's interesting, in fact, that even though the word 'opener' is a valid word, in the context of a 'can opener', say, it is not a valid comparative for open. It is wrong to say 'The light through the large window makes this room much opener than that one' - you should say it makes it 'much more open' instead. But you could say it made it 'much brighter'.
English is complicated. Let's not pretend that we know about some intentionally engineered structure in it when we're really just noticing patterns and correlations.
Is he more stupid or stupider? I would say stupid, stupider, stupidest, red, redder or more red, reddest, and brilliant, more brilliant, most brilliant, but smart, smarter, smartest.
There are probably a few exceptions, but it worked remarkably well during my few years.
But the noun placement is actually irrelevant here, as the point is that "grand" still precedes "rouge", and you'd never say "rouge avion grand" or even "avion rouge grand".
In French it becomes easier both to see that "big" modifies the composite entity "red plane", and that there is a difference in kind between the two "adjectives" (which now looks like too broad a term to be really useful). It's not just a matter of word order (syntax), there's a semantic hierarchy in play as well.
Some light googling seems to indicate that in German (my native language) the adjective order doesn’t really matter, but some say it actually does (citing pretty much exactly the same rules as in the linked article).
To my ears „grüner, großer Drachen“ doesn’t sound as correct as „großer, grüner Drachen“, but maybe that’s just my knowledge of English leaking into my German. It doesn’t sound entirely incorrect to me, either, not in the same way “green great dragon” does. Maybe German does have the same rules about adjective order, but they aren’t as strong? Maybe a teacher would put a wiggly line under wrongly ordered adjectives, but it wouldn’t actually be a serious mistake, just a weird stylistic choice?
Also, it’s entirely possible I actually was taught about adjective order, but have forgotten all about it. If you learn English for nine years (with either four or five lessons per week) you do lots of reading and writing, especially during the later years, actual texts from the real world and actual essays. It‘s very possible I picked it up through that and it was never necessary to explicitly teach me about adjective order.
I also remember being explicitly taught about some similar (but different) ordering in English, though I have mostly forgotten about it. I think time is always supposed to come last or something?
So “we are going to go to the airport with the bus tomorrow” would be correct (placing tomorrow at the beginning of the sentence would be, too, and would be the variant I would personally prefer), while “we are going to go to the airport tomorrow with the bus”, while still correct, would not be something you’d want to write.
Or maybe I’m misremembering, because that second sentence seems correct to me, just placing more of an emphasis on the means of transportation than the first one (i.e. you would use that one when someone already knows about your plans, but asked you how you will get to the airport). I don’t know. This is all a haze. I remember something about time and putting it last.
Note "by bus" and not "with the bus", which is technically correct ("How are you getting to the airport?" "We're going with the bus.") but sounds a bit odd; "We're taking the bus" or "We're going by bus" would be more natural.
After considering it more, I realized the only case in which "with the bus" is acceptable is when you are referring to "the bus" as a group of people, where you could plausibly say "the bus group". And that is why I considered changing the example to "with the shuttle" (as that sounded more plausible to me): because you are more likely to know a group of people on a shuttle than an entire bus.
we are going to go to the airport by bus tomorrow
we are going to go by bus to the airport tomorrow
tomorrow, we are going to go to the airport by bus
we are going to go to the airport tomorrow by bus
we are going to go tomorrow to the airport by bus
The last sentence sounds a little more awkward, but if you're emphasizing when the event is occurring, it would be fine. Similarly, in the right context:
to the airport, we are going to go by bus tomorrow
by bus, we are going to go to the airport tomorrow
This phenomenon is called topicalization.
> So “we are going to go to the airport with the bus tomorrow” would be correct
Actually you go by bus, or on the bus, never with the bus.
If you say 'expencive ugly car' you want to make a subjective statment about cost vs 'ugly expencive car' when you want to make an ascetic statement about an expencive car.
So, I think the general rule is context specific before innate trates. What about German?
- Time (TEmpo) - Causality (CAusalitá) - MOde (MOdo) - Location (LOcazione)
If they'd called it Zeit, Grund, Art, Lage, it would probably be a lot harder for both of us to remember! (Those are native German words for time, reason, manner, place.)
I never tried to remember the rules, I just read a lot and know if it sounds OK or not (or sometimes I don't). Using the rules on the fly would be too slow, anyway.