Here are some reflections on how cases in general relate to meaning in a sentence. There are 6 distinct cases in Latin: Nominative, Genitive, Dative, Accusative, Ablative, and Vocative; and there are vestiges of a seventh, the Locative.

Ablative of instrument or of means marks the means by which an action is carried out: oculīs vidēre, “to see with the eyes”. This is equivalent to the instrumental case found in some other languages.

In Latin the dative has two classes of meanings. The dative denotes an object not as caused by the action, or directly affected by it (like the accusative), but as reciprocally sharing in the action or receiving it consciously or actively.

: of, relating to, or being a grammatical case (see case entry 1 sense 3a) that typically marks a person, place, or thing from which someone or something else is separated or the source from which someone or something comes, and is also frequently used to indicate the cause of an event or condition or the instrument by …

Ablative materials are used to protect vehicles from atmospheric reentry, to protect rocket nozzles and ship hulls from propellant gas erosion, as protection from laser beams, and to protect land-based structures from high heat environments. As the charred surface is eroded, more char forms.

The Ablative of Respect is used without a preposition in the sentence. It shows in what respect something is being done. It is often used with the adjectives dīgnus and indīgnus, which mean “worthy” and “unworthy” respectively.

“In” with the accusative means into, onto, against… it has the idea of forward motion, whereas “in” with the ablative denotes simply position, in or on. “Sub” can also take both cases.

The inflection of nouns is called declension. The individual declensions are called cases, and together they form the case system. Nouns, pronouns, adjectives and participles are declined in six Cases: nominative, genitive, dative, accusative, ablative, and vocative and two Numbers (singular and plural).

The preposition in is one of a number of prepositions in Latin that can take both the accusative case and the ablative case. and in the ablative, it can mean either in, at, on, or upon.

Latin Prepositions and their Cases

The accusative case (abbreviated ACC) of a noun is the grammatical case used to mark the direct object of a transitive verb. The same case is used in many languages for the objects of (some or all) prepositions. It is usually combined with the nominative case (for example in Latin).