How to identify the 4 cases - a tip?
In most grammatical text, you will find the four German cases without a numbering; however, the nominative case is usually in the 1st position and the dative case in the 3rd position. I learned the four cases in a certain order which proved to be a great mnemonic aid.
1) Nominative, 2) Genitive, 3) Dative and 4) Akkusativ.
This may not flow with your logic, however let me explain why this might be the best tip ever: 1) The nominative case is the first and most important case. You will always have a nominative object (NO) in a sentence. In English, it is "S-V-O"= subject verb object. The NO is the subject. Learn to ask "Wer oder was?" = "Who or what?" to identify the NO. 2) The genitive case. It has been become very rare. People forget how to use it properly. There is a book "Der Dativ ist dem Genitiv sein Tod" and its title is incorrect and makes fun of the fact that people use the dative falsely where the genitive case is appropriate. If you want to impress, study up on the genitive. Why is it logical to come in the second place of a sentence? Often - not always - the genitive objects (GO) follow in the second position as the second object in a sentence right after the NO. Learn to ask: "Wessen?" = "Whose?" to identify the GO. E.g., "Die Frau des Mannes ist groß." Note the unusual occurrence of the letter "s" in the genitive case. If it sounds "s"sy, you are most likely dealing with a genitive case. E.g., "des Hundes"/"des Onkels" - "Wessen?" (Whose) etc. The letter "s" is attached at the end of the GO. You ask with a s-question word for the GO and so on. 3) The dative case - remember it as the 3rd case. Tilt the number three to the left - you got the letter "m" with three legs. The number three has three arms. Associate this case with the "m"-sound. Learn to ask: "(Mit) wem?" = "Whom?" to identify the DO. Note the letter m is both in the German and in the English question word, and the unusual occurence of the conjunction "mit" (another m-word). The letter m will be attached to adjectives, pronouns, etc. E.g. "Ich gehe mit meinem Mann" - "Mit wem?" or "Meinem Mann ist schlecht" - "My husband is feeling sick". 4) Accusative case. The 4th and last one. Either remember it is the last one left. Or you grew up like me with a battery charger ("Akku" - accumulator) that held 4 batteries. Best visual mnemonic aid ever. The accusative object (AO) is the classic object in a sentence. The thing that is being seen, manipulated, etc. It is the O in the SVO. "Er liest ein Buch" - "He reads a book". Learn to ask: "Wen oder was [sieht/manipuliert/liest] er?" - "ein Buch".
It is also helpful to think of the nominative case as "the nominator" and the accusative "the accused."
Super erklaert! Danke! Question regarding "Meinem Mann ist schlecht." "Meinem Mann" is the DO (Wem ist schlecht?). But if so, then there is no NO (subject) in the sentence. Is that possible?