If you're going to learn Latin, you need to know what the different noun cases are, because we're just getting started. There are different declension patterns depending on what class the word is, but I won't be getting into that here because I'm still learning that myself. This is just the basic stuff here.
This write-up closely follows this video: Latin's Case System, by latintutorial. Please watch it later for more details. I am writing this up strictly in English, and much of this terminology is universal, but all of this is specifically how they are used in Latin.
The subject of the sentence. Generally who or what is doing or experiencing something.
a. The girl is sleeping.
The subject complement after a stative verb.
a. Mark is a young man.
a. The mother of the girl. (AKA The girl's mother.)
Part of a whole.
a. A section of the orange.
a. A book of great renown.
a. A fear of zombies.
The indirect object of a transitive verb.
a. Tom threw the ball to Sam.
Reference (such as the benefactive, "for the benefit of").
a. Dave cooked dinner for Olivia.
Possession (not the same as the possessive).
a. I have a horse. (Literally, "There is to me a horse." This is the method Irish uses: "A horse is at me.")
The direct object of a transitive verb.
a. Tom threw the ball.
The object of certain prepositions (generally motion toward).
a. Jen is coming to the house.
b. The bird flew into the cage.
c. The children are running around the tree.
d. The hole goes through the floor.
e. The flower is near the tree.
f. The ship will be sailing across the ocean.
Duration of time.
a. We sleep for eight hours.
This is a bit of a catch-all. My main source glossed over this, so I brought in other sources to round it out:
Turns a noun phrase into an adverbial phrase.
a. The message was delivered by an owl.
b. She went for a walk with the dogs.
c. The Romance languages derive from Latin.
d. The apple is in the basket.
e. The painting is on the wall.
When something happens (not the same as duration).
a. I'm going on vacation in three days.
The object of certain prepositions (location or motion away from).
a. I live in the city.
b. He's coming from the office.
- Direct address.
a. Robert, how are you? (archaically: O Robert)
- Where someone or something is located. Only used with the names of cities, towns, and small islands (proper nouns such as "Rome", not common nouns such as "city") plus the three common nouns "humus (ground)", "rus (countryside/farm)", and "domus (house/home)". These do not take any preposition. (There are also two more nouns that take the locative, but they are more rarely used.)
a. All other locations take a preposition and the ablative case. See "ablative" above.
I don't know what you meant by "tenues". I assume that's a typo, but I don't know what you were going for there. "Aspiration" and "plosive" are just ways to describe sounds. "Aspirated" means with an extra puff of air, "plosives" are stop consonants (p, b, t, d, k, g).
[There is a weird glitch that's making the entry for "Locative" bump up against the entry for "Vocative" without any space. I've triple-checked my formatting and there's nothing I can do to fix it. It's on Duolingo's end, not mine. Hopefully it will resolve itself eventually.]
Since this is an initial overview, I would like to offer a small detail of the little I know, but may be useful (and subsequent responses will certainly be of help to me).
ABLATIVE is not exactly a "catch-all", but rather from your examples it seems to subsume the INSTRUMENTAL CASE within it, here in your iteration of Latin cases, whereas in Sanskrit, for one example, the instrumental case remains distinct, whereas Ancient Greek subsumes the instrumental within the dative case.
So, ablative and instrumental have specific grammatical identities that may be helpful to know on principle, within the Latin declension system (even if subsumed within one category they remain distinct linguistic concepts).
A general rule of thumb (more often right than wrong) is a stationary preposition or a moving away preposition takes the ablative, whereas other moving prepositions generally take the accusative This doesn't always hold true, but it especially helps in the beginning.
As far as I know, Latin speakers usually didn't have an opposition of aspirated plosives and tenues. Few would have been able to pronounce Greek loan words correctly.
There seems to have been some level of allophonic aspiration which lead to spellings as pulcher, but I think it was left to chance if this allophonic aspiration entered the spelling of a word.
At the same time, the point is to be pedagogical and prescriptive in this case: to teach Classical Latin as if coming from a perfect native speaker of the aristocratic class (for example -- please don't rip into this assumption :P) and to learn it as if from a perfect native speaker.
I'm not sure I got it right or not, but I think what you just said is plain horrible; I hear it on my ears going like "the point is to teach a disfigured and improper Latin as if it was all good and perfect"! Maybe I just drifted with the thought and you didn't mean what I understood at all, but if that's not the case, please remember that Duolingo could be the first and the largest teaching gateway ever that pumps the education of Latin to such a potentially very large mass of learners. When a language is taught wrong, it could stay wrong forever.
When a language is taught wrong, it could stay wrong forever.
You're giving Duolingo way too much credit. Even if someone completes a big tree on this site, it's only a jumping-off point toward learning a language. There is no substitute for in-person instruction from qualified, certified language instructors. Duolingo courses are put together by volunteers. Your fear that Duolingo will somehow ruin Latin is entirely unfounded.
I've read this a lot of times. I might need to publish an article on this.
If you suppose that /kʷ/ is a labialised phoneme, then there is no information on the articulatory position in the [ʷ]. The proper definition of ⟨ʷ⟩ in IPA is labialisation anyway.
This means, you should spell it as [k̟ʷɪs] or even [cʷɪs]. Besides, it should be impossible to pronounce [kᶣɪs], if the /k/ is not in fact [k̟]. This also shows that people who suppose there is no palatalisation (I don't mean affrication) of /k/ in Classical Latin should review their analysis.
I should think so, but the DL beta test isn't extensive enough to tell us how strict Latin speakers are re the difference between a village, town and city. The "spirit" of "Who is in town?"--which someone might well say in NYC--certainly seems apt (and more likely than "Who is in the city?").