The Isu language, unlike English but like certain other languages such as Latin, marks the grammatical case of a noun using various endings. The case of a noun essentially describes its role in the sentence. In English grammar, you might be familiar with the terms subject, direct object, etc. The case endings for the Isu language are as follows:

Grammatical Case Endings

There are a lot of cases and you may not be familiar with all the terms, so let's go over them. The nominative case is for the subject of the sentence: whoever or whatever is doing the action. However, the Isu language actually has two different nominative endings, depending on whether the noun is animate (describing a person) or inanimate (describing anything else). Note that the Isu may not necessarily consider humans to be animate. The genitive case indicates a possessor, very similar to how you would use the -'s ending (as in "Desmond's birthday") in English. The dative case indicates a receiver, what you would call the indirect object of the sentence in English. In the sentence "I gave my dog a bone," the dog would be in the dative case.

The accusative case marks the target of a verb, the direct object. Isu actually has three whole endings in the accusative. We have an animate ending like in the nominative case, but we also have two separate inanimate endings, what we'll call concrete and abstract. Concrete nouns describe things that physically exist, whereas abstract nouns describe concepts. These are essentially gendered endings like you might be familiar with in languages like Spanish or French, but in the case of the Isu language, grammatical gender has nothing to do with being male or female.

The locative case indicates the place where the action takes place, for example "in the Animus." The ablative case indicates something which the action is moving away from. For example, in the phrase "a call from my dad," the dad would be in the ablative case. The causal case indicates the beneficiary or purpose of an action, such as "for the creed." The instrumental case indicates a tool being used to perform an action. In the sentence "Assassinate the target with a hidden blade," the hidden blade would be in the instrumental case.

Additionally, Isu uses the infix -r- to indicate pluralization. To decline a noun, start with the stem, then add the plural marker if appropriate and finally add the ending for the appropriate case.

Personal pronouns are a special case. They sometimes use the same endings as regular nouns, but not always. Isu pronouns can be broken down into first-, second- and third-person in the singular and plural, just like in English.

Pronouns Singular First

Note that the instrumental case may not be accurate as the instrumental form of the second-person pronoun does behave differently from the other cases, and there are as yet no examples of the first-person singular pronoun in the instrumental case. Likely there's a vowel missing because "hmh" is not actually a syllable and very hard to pronounce.

Second

Third

The third-person singular pronoun has not actually appeared at all in any of the sources that have been released, but we can guess what it should look like by analogy with the third-person plural pronouns, the definite articles, and the number "one," all of which we'll get to later in this article.

Plural First

Second

Third

The definite article (like the English "the") is not required in the Isu language but can be used for emphasis in certain situations, such as when referring to "The Council" that seems to have ruled Isu society.

Definite Articles

The last concept we'll cover in this article is the word for the number one: oænos. This word is used to refer to a single person or object, but it can also mean "once." The word can even be doubled to mean "one and only one." Additionally, it can be pluralized to mean "everything" or "everyone": oænosr. It can also be negated to mean "nothing": ṇoænos.

More Isu Studies

You can find more articles on the Isu language linked here: Understanding the Isu Language: The Basics