The instrumental case (abbreviated INS or INSTR) is a grammatical case used to indicate that a noun is the instrument or means by or with which the subject achieves or accomplishes an action. The noun may be either a physical object or an abstract concept.
Modern English expresses the instrumental meaning by use of adverbial phrases that begin with the words with, by, or using then followed by the noun indicating the instrument:
Technical descriptions often use the phrase "by means of", which is similar to "by use of", as in:
This can be replaced by "via", which is a Latin ablative of the nominative (viā) via, meaning road, route, or way. In the ablative this means by way of.
The instrumental case appears in Old English, Old Saxon, Georgian, Armenian, Basque, Sanskrit, and the Balto-Slavic languages. An instrumental/comitative case is arguably present in Turkish and other Altaic languages, as well as in Tamil. Also, Uralic languages reuse the adessive case where available, locative case if not, to mark the same category, or comitative case (Estonian). For example, the Finnish kirjoitan kynällä does not mean "I write on a pen", but "I write using a pen", even if the adessive -llä is used. In Ob-Ugric languages, the same category may also mark agents with verbs that use an ergative alignment, like "I give you, using a pen".
The instrumental case is notably used in Russian, where the case is called творительный падеж (tvoritel'nyj padež) though similar usages also can be found in other Balto-Slavic languages. In most declension paradigms, the instrumental case in Russian can generally be distinguished by the -ом ("-om") suffix for most masculine and neuter nouns, the -ою/-oй ("-oju"/"-oj") suffix for most feminine nouns and -ами ("-ami") for any of the three genders in the plural.
Just as in English the preposition "with" can express instrumental ("using, by means of"), comitative ("in the company of"), and a number of other semantic relations, the instrumental case in Russian is not limited to its instrumental thematic role. It is also used to denote:
The Russian instrumental case is also used with verbs of use and control (to own, to manage, to abuse, to rule, to possess, etc.), attitude (to be proud of, to threaten (with), to value, to be interested (in), to admire, to be obsessed (with), etc.), reciprocal action (to share, to exchange), and some other verbs.
Though the instrumental case does not exist in many languages, some languages use other cases to denote the means, or instrument, of an action. In Classical Greek, for example, the dative case is used as the instrumental case. This can be seen in the sentence "..με κτείνει δόλῳ," or "..me ktenei dolôi" (Book IX, line 407 of the Odyssey), which means "he kills me with a bait". Here, "δόλῳ," the dative of "δόλος" ("dolos" – a bait) is used as the instrumental case (the means or instrument here is, obviously, the bait). In Latin the instrumental case has merged with the ablative, thus the ablative case has the same functions. For example, ipso facto can be translated as "by the fact itself", while oculīs vidēre means "to see with one's eyes".
In Modern English, the word why is one instance of an etymologically instrumental declension. Though not commonly known to be of pronominal origin, it was, in fact, inherited from Old English hwȳ, which was the declension of hwæt (now what) in the Old English instrumental case – a grammatical feature rare even in Old English. The modern instrumental case (as present in why) does not bear the meaning of instrument, but of purpose, cause, or reason: rather, the closely related form how is used to express instrument, way, or means.
In Standard Assamese (এ)ৰে (e)re indicates the instrumental case. (এ)দি (e)di does the job in some dialects.
The functions of the Proto-Indo-European instrumental case were taken over by the dative, so that the Greek dative has functions belonging to the Proto-Indo-European dative, instrumental, and locative. This is the case with the bare dative, and the dative with the preposition σύν sýn "with". It is possible, however, that Mycenean Greek had the instrumental case, which was later replaced by dative in all the Greek dialects.
While Old High German possessed a rudimentary instrumental case, its function was replaced with the dative in Middle High German, comparable with English and Ancient Greek, with a construction of "mit" (with) + dative clause (in English, the objective case is used). For example:
"Hans schrieb mit einem Stifte*."
(John [nominative] wrote with a [dative] pencil [dative].)
*the German dative -e is not used in any common conversation; it is only implented here for a better demonstration.
Just as above, the object with which the action is done or completed is declined. For example:
The instrumental in Armenian is denoted by the -ով (-ov) suffix to say that an action is done by, with or through an agent.
Instrumental is usually used to denote a noun with which the action is done, i.e. "Idem autom"-"I'm going by means of a car", "Jedem vilicom"-"I eat with a fork", "Prenosi se zrakom"-"it's transferred through air", "Prožeta je bijesom" – "She's consumed by anger". The instrumental preposition s(a), meaning "with", is supposed to be dropped in this usage, but it's often kept in casual speech when talking about objects in usage such as a pen, a hammer, a car etc. Instrumental can also denote company, in which case s(a) is obligatory, i.e. "Pričali smo sa svima"-"We talked with everyone", "Došao je s roditeljima"-"He came with his parents", "Šetala se sa psom"-"She was taking a walk with her dog". Dropping s(a) in this case would either make the sentences incorrect, or change their meaning entirely because dative, locative and instrumental share the same form in the plural, so the examples "Pričali smo svima" i "Došao je roditeljima" would come to mean "We've been talking at everyone" and "He came to his parents". Instrumental is also used with certain spatial prepositions like među (between), nad (above), pod (underneath), pred (in front of), za (after). Note the difference between these prepositions and similar ones used for genitive with an -i suffix: između, iznad, ispod, ispred, iza. It is also used without proposition: "Putujem zemljom" (I'm travelling the country), "Hodam plažom" (I'm walking along a beach). It is also used to show how long or when in a larger scope of time something happens: "Nema ih godinama" (they haven't come in years), "S vremenom će proći" (it will pass in time), "Jednom tjednom" (once a week)
The instrumental case is present in the Hungarian language, where it serves several purposes. The main purpose is the same as the above, i.e. the means with which an action occurs. It has a role in the -(t)at- causative form of verbs, that is, the form of a verb that shows the subject caused someone else to action the verb. In this sense, the instrumental case is used to mark the person that was caused to execute the action expressed by the verb. It is also used to quantify or qualify words such as 'better' or 'ago', such as sokkal jobban 'much better' (literally 'with-much better'); hét évvel ezelőtt 'seven years ago' (literally 'seven with-years before this').
Finnish has a historic, marginal instructive case (-n), but in practice the adessive case (-lla/-llä) is used instead outside lexicalised fixed expressions, even though the adessive literally means 'on top', e.g. vasaralla 'using a hammer' (instrumental meaning) or 'on a hammer' (locative meaning). (Vasaroin 'using hammers' is plausible and understandable, but not common in use.)
Nahuatl uses the suffix -tica to indicate the instrumental case. For example, in the sentence ātlān ācaltica in huāllahqueh 'they came on the water by boat', ācalli means 'boat' and ācaltica means 'by (use of a) boat'.
Turkish uses the conjunction ile ("with"), and its suffixed form -(y)lA (realised as -(y)la or -(y)le, depending on the dominant vowel of the noun—see vowel harmony) to indicate the instrumental case. For example, in the sentence Arabayla geldi 'he came by (the use of a) car', araba means 'car' and arabayla means 'by (the use of a) car, with a car'.
The original Proto-Turkic instrumental case suffix was -n, which is less productive today but is preserved in common words like yazın ("during the summer"), kışın ("during the winter"), öğlen ("at noon"), and yayan ("by foot", "on foot"). It became less productive in most Oghuz Turkic languages. The conjunction ile ("with") in Turkish has semantically expanded to fill the gap (kürek ile or kürekle, meaning "with the shovel" > "using the shovel"), being used as an instrumental marker, and the suffix -(y)lA (-le, -la, -yle, -yla) is a form of ile which has been grammaticalized into an agglutinative suffix as a result of quick speech, becoming an enclitic.
In Japanese, the post-positional particle で de indicates the instrumental case.
The instrumental in the North Caucasian language Vainakhish is denoted by the -ца / -аца / -ица (-tsa / -atsa / -itsa) suffix to describes an action which is done with an agent: