Better will be: \w+us(?=\W)
\w - not word ending
+ - one or more times
(?= ) - look ahead
\W - word ending

Tekstaro records the actual use. PMEG writes about the correct use. Everyone has to make a decision where in-between to stand. To my understanding this applies to all human languages.

Tekstaro records nothing. It searches usage of the query in the set of the documents, added to it.
Similar resouces has other languages, but they are more rich.

I think the problem for English speakers is that Esperanto really doesn't have a word or construct that means "should" the way English means it. I haven't studied a lot of languages, and am certainly no linguist, but my impression is that words like "should" aren't actually that common across languages. English, however, loves the word. We sit it down and dance on top of it and all around it, and use it every chance we get. So when we want to say the English should-thing in Esperanto, which we want to do all the time... uh oh. There's no straightforward mapping. But we love "should" so much that this keeps coming up, and thus can be somewhat troublesome, especially for beginners.

Devintus gets pressed into service. It's horrible, though. It's ugly and it doesn't really mean what we want it to mean, but it kinda does sorta but not really, so we throw it out there in a hand-wavy, you know what I mean sort of way, and hope people don't call us on it.

The other option is misusing the conditional. We do that, too, because the conditional is also a kinda-sorta match that really isn't.

I've been thinking about this, and what "should" really means. And what I've come up with is that all "should" is really doing is identifying the best course of action out of some set of actions. It doesn't imply that you will take that action. It just says "if you put the set of possible actions in a list from most favorable to least, this one is on the top. This is the recommended action. But, however strongly it might be 'recommended', it still isn't a compelled action".

I'm thinking that maybe the best way to express this is with a "plejbonus se...". It would be best if...

Plejbonus se mi iros al la vendejo. I should go to the store. No one is making me go to the store. I could easily do something else. But (because of some reason) it would be best if I went to the store. I would be a fool if I didn't go to the store, but I still have that option.

To me that seems to capture it. Although I haven't run through every possible permutation where "should" gets used, so I'm likely missing something. I feel like it works well, though, at least in this situation.

What do others think about this particular method of expression for "should"? Have I missed any subtleties? Seems workable to me, and it definitely kills "devintus", which fully deserves to die in my opinion.

Plejbonus - tro peza vorto.
You could say simpler:
Estus plej/pli bone, ke mi iru al la vendejo.

Estus bone se estus en Esperanto ia verbo, kiu pridiras konduton aŭ staton, kiu estas rekomendinda, preferinda, bezonata aŭ atendata.
redaktinte aldonis jenon:
- Oni devas aĉeti la ilon. La ilo estas aĉetenda.
- Oni ***as aĉeti la ilon. La ilo estas aĉetinda.
- Oni povas aĉeti la ilon. La ilo estas aĉetebla.

-- pardonon pri mia mesaĝo en Esperanto.

sudanglo:
PM-K, the Tekstaro is a corpus created for language research (millions of words from the very earliest writings to recent usage) which allows you to check current and historical usage in Esperanto.

PM-K, If you want to know the truth about devus, povus and volus, get to know how to search the Tekstaro, and then think how you would translate the usages you find into English. Then cross-reference with the explanations in PMEG, or look up the examples in PIV.

If you want to look at -us with other verbs you will need to enter the search as \w+us (backslash w + us)

Just took a look at that site. Strange interface, but I'm sure I can figure it out.

Thanks for the heads up. It kind of dovetails with something else that I was thinking recently, which is that to really understand this language I'm probably going to have to spend a lot of time reverse-engineering texts to see how various words and phrases are actually used.

Plejbonus - tro peza vorto.

It has three syllables. I wouldn't really put that in the "tro peza" category. Your solution has five syllables to say the same thing, which I think of as actually a little heavier. Certainly wordier.

It's just a matter of taste\style, I think. I tend to prefer compound words, if they're short enough, but others tend to break them up. Either style is fine.
"Plejboni" (to be best) is a perfectly workable construct. It might not be an expression you've encountered before, but that doesn't make it any heavier or more complicated, burdensome, etc.

PM-K - quite often the definitions and examples in PIV will be enough to set you on the right path. But if they aren't sufficient it can be very useful to hop across to the Tekstaro, and quite simple searches (without the complex syntax) will often be adequate..

Remember that clicking on the search results will give you more context and a further click even more. If you want help with interpreting any search result, just ask.

By the way, just looked in PIV and found this on -us usage for devi.

Rim. Ĉe la indikativa preterito, devi signifas, ke oni obeis la devon: mi devis vin puni (k mi vin efektive punis). Por esprimi, ke oni ne obeis la devon, oni uzas kondicionalon: mi devus vin puni (sed mi vin ne punas); mi estus devinta vin puni (sed ne punis vin).

PrimeMinisterK:And what I am saying is that if "My devus aĉeti melon" means "I should buy a badger," then shouldn't "Vere mi devus aĉeti la aŭton" mean "I really should buy the car"?

After reading through this thread, I think it is safe to assume that "should" plays various, quite different roles in English, and that there is no 1-to-1 mapping or recipe for translating it into Esperanto without further context.

Maybe a rule of thumb could be: If any notion of obligation (devo) is implied, go with devi. If it is not about an obligation (if it is about the best option in a list of possible actions, as riot very aptly worded it), keep your hands away from devi.

"Vere mi devus aĉeti la aŭton": I really would have the obligation to buy the car. For example: Estas bone, ke mi ne subskribis antaŭaĉetkontraton (pre-purchase contract). Ĉar se mi surkribis ĝin, mi vere devus aĉeti la aŭton.

"Mi vere aĉetu la aŭton": I really want me to buy this car. Or somebody else wants me to buy this car. This is really hard to render in English, because you don't have an optative/jussive/hortative in English (except in some ritual phrases like "Long live the queen" or "thy kingdom come").