accusative and nominative cases
i was looking through my google docs, reading through a document i made for german and i found these. i know duolingo already has notes for this but if you're anything like me and had difficulty understanding them at first then i guess you might be able to get something out of these. i think they go a bit more in depth with nominative and accusative cases but i haven't read duolingo's version of the notes in a hot minute so i'm not sure :'D.. anyways, i hope these will help at least one person who's just starting out german. if any of these are wrong, please correct me :0
Nominative and Accusative cases:
Nominative: person/thing doing the action Accusative: the thing (or object) receiving the action
“She sees a ball”
She - nominative Sees - action/verb A Ball - accusative
To help you remember the two I’d apply the words to a crime. Let’ say a woman accuses a man of a crime. Accuse is our action/verb. The woman is the one accusing the man of the crime and therefore “the woman” is the nominative. The man is the one who is being accused, the act of accusation is being done to him and therefore he is the accusative.
Wir essen Brot. We are (nominative) eating (action) bread (accusative). Du isst einen Apfel. You are (nominative) eating (action) an apple (accusative).
Real quickly I’d like to write a note about that second sentence; “Du isst einen Apfel”. Since apple is a noun, we capitalize it. When the noun in a sentence is accusative and is also masculine, we change the sentence around a bit, if that makes any sense. Originally, the sentence would’ve been “Du isst ein Apfel” but since “Apfel” is a masculine accusative, we change “ein” to “einen”. Same with “the”. Take this example:
Wir essen den Apfel. We (nominative) are eating (action) the apple (accusative)
Originally, this sentence would’ve been “Wir essen der Apfel” but once again since “Apfel” is a masculine accusative, we say “den”.
Whatever works for you, I suppose is fine, but direct objects aren't always accusative.
Some verbs use dative objects: https://www.thoughtco.com/frequently-used-german-dative-verbs-4071410
Some even use genitive objects: https://www.fluentu.com/blog/german/german-genitive/
You have to scroll down a bit on that last page to get to the verbs.
It gets worse when one gets to prepositions; some take one case, some another, still others the third. Some prepositions even change case depending on the verb used! https://www.thoughtco.com/two-way-doubtful-prepositions-in-german-1444444
but direct objects aren't always accusative.
Interesting—before looking at your links I'd never heard or thought of it like that. In all of the sources I used, it's always been that dative verbs like "folgen", "helfen", "danken" usw. have no direct object; i.e. they only have an indirect object.
I can see the argument for your thinking, but I've always found it easiest to just think:
nominative = subject
accusative = direct object
dative = indirect object
genitive = 'possessive' object
With the exception of prepositions that just seem to demand a case willy-nilly :P
P.S. And a disadvantage of viewing all of these as direct objects is in the whole transitive vs. intransitive argument, used to determine if a verb uses "sein" or "haben" in the perfect tenses.
A very, very, very, very, very good rule of thumb is that all transitive verbs take "haben"; however, that rule of thumb is only as useful as it is if you count transitive as taking a direct accusative object. Once you say that "dir" is a direct object in the sentence "Ich folge dir.", then you're calling "folgen" a transitive verb which would mean that it should form the perfect with "haben"; but as we all know ;-) the perfect form of my sentence above would be "Ich bin dir gefolgt".
So, that's another reason why I would hesitate to say that a direct object doesn't have to be accusative.
"Du isst ein Apfel" is always wrong. Which form of the article (definite: der, die, das ; indefinite: ein, eine, ein) must be used depends on the gender of the noun and on the case (Nominativ, Genitiv, Dativ, Akkusativ). In this sentence the case is accusative, the gender of "Apfel" ist masculine. The question would be as followed: "Wen oder was isst du?" - einen Apfel
It's not the sentence that is changed but the form of the noun/article (->Deklination/Beugung). Nom. ein Apfel/der Apfel Gen. eines Apfels/des Apfels Dat. einem Apfel/dem Apfel Akk. einen Apfel/den Apfel
Here are examples with nouns of different genders: masculine noun "der/ein Apfel" -> Du isst einen Apfel. feminine noun "die/eine Orange" -> Du isst eine Orange. neutral noun "das/ein Ei" -> Du isst ein Ei.
I hope this helps.