Editing Instrumental case (section)

==General discussion==
The instrumental case appears in this [[Russian grammar|Russian]] sentence:
{{fs interlinear|indent=3|lang = ru
|Я написал письмо пером.
|Ya napisal pis'mo perom.
|I wrote {(the) letter} {[with] (a) quill pen.}|}}

Here, the [[inflection]] of the noun indicates its instrumental role: the [[nominative case|nominative]] ''перо'' changes its ending to become ''пером''.

Modern English expresses the instrumental meaning by use of adverbial phrases that begin with the words ''with'', ''by'', or ''using'', followed by the noun indicating the ''instrument'':

:''I wrote the note with a pen.''
:''I wrote the note (by) using a pen.''

Technical descriptions often use the phrase "by means of", which is similar to "by use of", as in:

:''I wrote the note by means of a pen.''
:''I wrote the note by use of a pen.''

This can be replaced by "via", which is a Latin [[ablative case|ablative]] of the nominative (viā) ''via'', meaning road, route, or way. In the ablative it means ''by way of''.

The instrumental case appears in [[Old English language|Old English]], [[Old Saxon language|Old Saxon]], [[Georgian language|Georgian]], [[Armenian language|Armenian]], [[Basque language|Basque]], [[Sanskrit]], and the [[Balto-Slavic languages]]. An instrumental/[[comitative case]] is arguably present in [[Turkish language|Turkish]] as well as in [[Tamil language|Tamil]]. Also, Uralic languages reuse the [[adessive case]] where available, [[locative case]] if not, to mark the same category, or [[comitative case]] ([[Estonian language|Estonian]]). For example, the [[Finnish language|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–absolutive alignment|ergative alignment]], for instance, "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 agent in a passive voice construction. E.g.: "Книга написана Марком Твеном" ("The book was written by Mark Twain"). Here, "Марком Твеном" ("by Mark Twain") is "Марк Твен" ("Mark Twain") in the instrumental case.
* a predicate with infinitive, future tense, imperative, conditional and gerund of the verbs "быть" and "являться" (both meaning 'to be') (for example, "я хочу быть врачом", "не будь трусом" translate as "I want to be a doctor" and "don't be a coward", with the nouns in the instrumental case).
* a predicate with a number of other verbs, denoting state, appearance, manner, consideration, etc.
* parts of the day, seasons of the year, and some other temporal relations.  For example, the sentence "я работаю утром" (ja rabotaju utrom) means "I work in the morning". The word утро (utro, "morning") in its instrumental case denotes the time in which the action (in the case of this example, "working") takes place ("in the morning").
* similarity. For example, the phrases "выть волком," "умереть героем," "лететь стрелой" (to howl like a wolf, to die like a hero, to fly like an arrow) use nouns in the instrumental case.
* location, when used with prepositions "behind", "in front of", "under", "above", "next to", and "between"

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 [[Ancient Greek language|Classical Greek]], for example, the [[dative case]] is used as the instrumental case. This can be seen in the sentence "{{lang|grc|..με κτείνει δόλῳ}}," or "..me ktenei dolôi" (Book IX, line 407 of the [[Odyssey]]), which means "he kills me with a bait".  Here, "{{lang|grc|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 case|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 language|English]], the word ''why'' is one instance of an etymologically instrumental [[declension]]. Though not commonly known to be of [[Interrogative pronoun|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{{spaced ndash}}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 phrases such as "The more, the merrier", the word ''the'' derives from the instrumental case of the demonstrative pronoun related to the modern English word ''that''.<ref>{{Cite web |title=Instrumental Case {{!}} Department of Classics |url=https://classics.osu.edu/Undergraduate-Studies/Latin-Program/Grammar/Cases/English-Case/instrumental-case |access-date=2023-12-10 |website=classics.osu.edu}}</ref>