Nota accusativi is a grammatical term meaning "denoting accusative case". It is generally applied to linguistic indicators of the accusative case. An example is the use of the preposition a in Spanish to indicate an animate direct object (the "personal a"): "Jorge llama a María".
Officially, in Esperanto, the sufix letter "n" is used to mark an accusative. But a few modern speakers use the unofficial preposition "na" instead of the final "n".
- Mi havas domon.
- Mi havas na domo.
- I have a house.
Ani ro'eh et ha-kelev. אני רואה את הכלב
I see the dog.
אני רואה את כלבי
I see my dog
אני רואה את דניאל
I see Daniel
On the other hand, "I see a dog" is simply "Ani ro'eh kelev." אני רואה כלב 
This example is obviously a specialized use of the nota accusativi, since Hebrew does not use the nota accusativi unless the noun in question is definite.
In Japanese, the particle "を" (pronounced "お" o) is the direct object marker and marks the recipient of an action.
In Toki Pona, the word e is used to mark accusative.
In other languages, especially those that indicate case grammatically, there is usually a separate form (for each declension if declensions exist) to indicate the accusative case. The nota accusativi should not be confused with such case forms, as the term nota accusativi denotes a separate particle indicating the accusative case.
- Bubeník, Vít (2006). From Case to Adposition: The Development of Configurational Syntax in Indo-European Languages. John Benjamins. p. 54. ISBN 90-272-4795-1.