The partitive case (abbreviated PTV or more ambiguously PART) is a grammatical case which denotes "partialness", "without result", or "without specific identity". It is also used in contexts where a subgroup is selected from a larger group, or with numbers.
In the Finnic languages, such as Finnish and Estonian, this case is often used to express unknown identities and irresultative actions. For example, it is found in the following circumstances, with the characteristic ending of -a or -ta:
Where not mentioned, the accusative case would be ungrammatical. For example, the partitive must always be used after singular numerals.
As an example of the irresultative meaning of the partitive, ammuin karhun (accusative) means "I shot the bear (dead)", whereas ammuin karhua (partitive) means "I shot (at) the bear" without specifying if it was even hit. Notice that Finnish has no native future tense, so that the partitive provides an important reference to the present as opposed to the future. Thus luen kirjaa means "I am reading a/the book" whereas luen kirjan means "I will read a/the book". Thus "luen" can mean "I am reading" or "I will read" depending on the case form of the word that follows. The partitive form kirjaa indicates incompleted action and hence the meaning of the verb form is present tense. The accusative form kirjan indicates completed action when used with the past tense verb but indicates planned future action when used with a verb in the present tense. Hence luen kirjan means "I will read the book".
The case with an unspecified identity is onko teillä kirjoja, which uses the partitive, because it refers to unspecified books, as contrasted to nominative onko teillä (ne) kirjat?, which means "do you have (those) books?"
The partitive case comes from the older ablative case. This meaning is preserved e.g. in kotoa (from home), takaa (from behind), where it means "from".
A Western Finnish dialectal phenomenon seen in some dialects is the assimilation of the final -a into a preceding vowel, thus making the chroneme the partitive marker. For example, suurii -> suuria "some big --".
1. It appears after numbers larger than 6:
This can be replaced with kää´uc ?âustõõ.
2. It is also used with certain postpositions:
This can be replaced with kuä´? vuâstta.
3. It can be used with the comparative to express that which is being compared:
This would nowadays more than likely be replaced by pue´rab ko kå´ll
The Russian language usually uses the genitive case to express partialness. However, some Russian mass nouns have developed a distinct partitive case, also referred to as the "second genitive case". The partitive arose from the merger of the declensions of *-? and *-? stem nouns in Old East Slavic, which left the former *-? stem genitive suffix available for a specialized use. In modern Russian, use of the partitive case is often facultative. In many situations, the partitive and the genitive can be used almost synonymously: ?, cháshka cháyu (partitive) and ? cháshka cháya (genitive) both mean "a cup of tea"; ?, mnógo dýmu (partitive) and ? mnógo dýma (genitive) both mean "lots of smoke". The partitive variant is preferred with verbs: ?, výpit' cháyu, "to have a drink of tea". The genitive variant is used more frequently when the mass noun is modified by an adjective: ? cháshka goryáchevo cháya, "a cup of hot tea".