The comitative case (abbreviated COM) is a grammatical case that denotes accompaniment.:17-23 In English, the preposition "with", in the sense of "in company with" or "together with", plays a substantially similar role (other uses of "with", like in the meaning of "using" or "by means of" (I cut bread with a knife), correspond to the instrumental case or related cases).
Comitative case encodes a relationship of "accompaniment" between two participants in an event, called the "accompanier" and the "companion". In addition, there is a "relator" (which can be of multiple lexical categories, but is most commonly an affix or adposition).:17-18 Use of Comitative case gives prominence to the accompanier.:602 This Italian sentence is an example:
In this case, il professore is the accompanier, i suoi studenti is the companion, and con is the relator. As the accompanier, il professore is the most prominent.
Animacy also plays a major role in most languages with a comitative case. One group of languages requires both the accompanier and the companion to be either human or animate. Another group requires both to be in the same category: both human or both animate. A third group requires an animate accompanier and an inanimate companion. Other languages have no restrictions based on animacy.:603-604
The comitative relates to an accompanier and a companion, and the instrumental relates to an agent, an object, and a patient.:593 Enrique Palancar defines the role of Instrumental case as 'the role played by the object the Agent manipulates to achieve a change of state of the Patient.' Even though the difference is straightforward, because the instrumental and the comitative are expressed the same way in many languages, including English, it is often difficult to separate them.
Russian is one of many languages that differentiate morphologically between instrumental and comitative:
In Russian, the comitative is marked by adding a preposition s and by declining the companion in the instrumental case. In the instrumental case, the object is declined, but no preposition is added.
The comitative case is often confused with the associative case. Before the term comitative was applied to the accompanier-companion relationship, the relationship was often called associative case, a term still used by some linguists.
It is important to distinguish between the comitative and the associative because the associative also refers to a specific variety of the comitative case that is used in Hungarian.:605
Grammatical case is a category of inflectional morphology. The comitative case is an expression of the comitative semantic relation through inflectional affixation, by prefixes, suffixes and circumfixes. Although all three major types of affixes are used in at least a few languages, suffixes are the most common expression. Languages which use affixation to express the comitative include Hungarian, which uses suffixes; Totonac, which uses prefixes; and Chuckchi, which uses circumfixes.:602
Comitative relations are also commonly expressed by using adpositions: prepositions, postpositions and circumpositions. Examples of languages that use adpositional constructions to express comitative relations are French, which uses prepositions; Wayãpi, which uses postpositions; and Bambara, which uses circumpositions.:603
The final way in which comitative relations can be expressed is by serial-verb constructions. In these languages, the comitative marker is usually a verb whose basic meaning is "to follow". A language which marks comitative relations with serial-verb constructions is Chinese.:603
French uses prepositions to express the comitative semantic relation.
In this case, the preposition "avec" is used to express the comitative semantic relation. The preposition "avec" is the standard comitative marker in French; however, French has a special case, the ornative case, a variety of comitative for bodily property or clothes[clarification needed]. The French ornative marker is "à".:603
In Latvian, both instrumental and comitative are expressed with the preposition ar:102 However, it is used only when the companion is in accusative and singular or when it is in dative and plural. Otherwise the co-ordinating conjunction un is used.:21
In the example above, ar is used because Rudolf, the companion, is in accusative and singular. Below, it is used in the other case that it is allowed, with a dative plural companion.
In Estonian, the Comitative (kaasaütlev) marker is the suffix "-ga".:90
In Finnish, the comitative case (komitatiivi) has the suffix -ne with adjectives and -ne- + a mandatory possessive suffix with the main noun. There is no singular-plural distinction; only the plural of the comitative is used in both singular and plural senses, thus it appears always as -ine-. For instance, "with their big ships" is
while "with his/her big ships" is
It is rarely used and is mainly a feature of the formal literary language, appearing very rarely in everyday speech.
The regular "with" is expressed with the postposition kanssa, thus this form is used in most cases, e.g. suurien laivojensa kanssa "with their big ships". The two forms may contrast, however, since the comitative always comes with the possessive suffix, and thus can be only used when the agent has possession of some sort over the main noun. For instance, Ulkoministeri jatkaa kollegoineen neuvotteluja sissien kanssa, "The foreign minister, with [assistance from] his colleagues, continues the negotiations with the guerrillas", has kollegoineen "with his colleagues" contrasted with sissien kanssa "with the guerrillas", the former "possessed", the latter not.
Colloquial Finnish also has the postposition kaa, developed after kanssa and cognate to the Estonian -ga. With pronouns, it is used as a suffix, -kaa.
As there are many Sami languages there are variations between them. In the largest Sami language, Northern Sami, the comitative case means either communion, fellowship, connection - or instrument, tool. It can be used either as an object or as an adverbial.
It is expressed through the suffix -in in the singular and -iguin in the plural.
An example of the object use in Northern Sami is "Dat láve álo riidalit isidiin", meaning "She always argues with her husband". An example of the adverbial use is "Mun ?álán bleahkain", meaning "I write with ink".
In Hungarian, comitative case is marked by the suffix "-stul/-stül", as shown in the example below.
However, the comitative case marker cannot be used if the companion has a plural marker. So when the comitative marker is added to a noun, it obscures whether that noun is singular or plural.
Chukchi uses a circumfix to express comitative case.
In the example, the circumfix - is attached to the root "gun" to express comitative.
In Drehu, there are two prepositions which can be used to mark comitative. Which of the prepositions is used is determined by the classes of the accompanee and companion.
The comitative marker in Hausa is the preposition "dà". In Hausa, a prepositional phrase marked for comitative can be moved to the front of the sentence for emphasis, as shown in the examples below.
In Hausa it is ungrammatical to do the same with coordinating conjunctions. For example, if the companions were "dog and cat", it would be ungrammatical to move either "dog" or "cat" to the front of the sentence for emphasis, while it is grammatical to do so when there is a comitative marker rather than a conjunction.