That's absolutely wrong that, "I have no peach," is not proper! It is 100% proper to say, "I have no peach."
"I ain't got no peach," is said by people who are either uneducated or who choose to speak in an ignorant vernacular.
It might not be grammatically wrong to say "I have no peach", but it is not a construction I have ever heard in normal speech (in British English). "I have no peaches" would be more likely.
And to describe people who would use "I ain't got no peach" as uneducated or using an ignorant vernacular is somewhat perjorative: "ain't" may not be standard English and shouldn't be used in formal contexts, but it is perfectly normal in many dialects and informal settings in both Britain and North America (and possibly also in Australia and New Zealand).
I say things like "I have no peach" all the time; seems a more poignant statement to me. In the first couple hundred results in the Corpus of Contemporary American English, many things following "I have no" are somewhat more abstract (although countable): choice, idea, opinion, clue, excuse. However, there's also "I have no fixed routine"; "I have no stable"; "I have no brother"; and "I have no country."
"ain't got no peach" is a double negative. If you don't have no peach, then you have a peach or peaches. Otherwise, you have no peach.
I wrote "...people who choose to speak in an ignorant vernacular." I wasn't calling the people who speak this way ignorant, since they speak this way by choice.
They may not "choose" to talk like that: it may be the only way they know.
And even if they do choose, it's not necessarily ignorant - it may be a conscious decision to fit in with the norms of a particular group.
I agree with the second part, a conscious choice. And in the first part, if that's the only way they know, then that by definition is ignorance--being ignorant of the proper grammar.
People can say that in spoken English it just isn't a proper way. Also you may see or hear people say ' I ain't got no peach'
Is there a rule in Ukrainian for when a noun in genitive case ends in "-а" versus "-у"? For example,
This is confusing because in Russian "-а" is the norm for genitive. "-у" tends to be a locative and dative declension.
If you can read in ukrainian: https://uk.wikipedia.org/wiki/%D0%A0%D0%BE%D0%B4%D0%BE%D0%B2%D0%B8%D0%B9_%D0%B2%D1%96%D0%B4%D0%BC%D1%96%D0%BD%D0%BE%D0%BA_%D0%BE%D0%B4%D0%BD%D0%B8%D0%BD%D0%B8_%D1%96%D0%BC%D0%B5%D0%BD%D0%BD%D0%B8%D0%BA%D1%96%D0%B2_%D1%87%D0%BE%D0%BB%D0%BE%D0%B2%D1%96%D1%87%D0%BE%D0%B3%D0%BE_%D1%80%D0%BE%D0%B4%D1%83_%D0%B4%D1%80%D1%83%D0%B3%D0%BE%D1%97_%D0%B2%D1%96%D0%B4%D0%BC%D1%96%D0%BD%D0%B8
I can read it, but I am learning the language on Duolingo, so I don't understand what I'm reading
there is a lot to tranlate and write it here, but you can google-translate it
I do not know your native language, but ukrainian-english translation in google works the best
or I can translate some basics from tables later
The trouble is that having used Google translate, it also translates the words that you want left in Ukrainian as examples etc. I'm sure somewhere there must be an English language explanation ... the only one I've found so far is here: http://www.ukrainianlanguage.org.uk/read/unit07/page7-3.htm
"Whilst most masculine nouns in the genitive end in а or я, there are certain categories of nouns (e.g. abstract concepts, weights and measures, mass nous, locations and institutions, emotions and states of mind, natural phenomena etc.) which mostly have an ending in у or ю, e.g. університет – університету, дощ – дощу, ідеал – ідеалу etc.
In some nouns a change in genitive ending also denotes a change of meaning, e.g. рака – (of a) lobster, раку – (of) cancer, соняшника – (of) sunflower, соняшнику – (of) sunflower seed. You need to be aware of this point, but it is not covered in detail in this course."
unfortunately ukrainian is not popular for learning, that's why there are no much rules of ukrainian language in english
Is "I don't have the peach" wrong?
I know the course doesn't accept things like "I have the peach" for "У мене є персик" (about the only time it doesn't accept both kinds of articles indiscriminately) and I figure that's because the sentence is about existence of any peach rather than location of a specific peach. But I wouldn't have thought there'd be a similar distinction for negative statements.
There's nothing to specify a definite peach, so "the" is not a natural construction
But does Ukrainian have a way to go about pithily specifying a definite peach that I don't happen to have at the moment (like maybe it fell out of the picnic basket in my trunk without my noticing and now I've lugged the basket quite a ways for the picnic)?
Would that have to be "Я не маю персика?"
Yes. У мене немає того персика./Я не маю того персика. "I don't have that peach."
If I don't have a sausage, then I guess it's okay that you don't have a peach.