jv-conjugator

For all your Japanese verb conjugation needs

https://www.npmjs.com/package/jv-conjugator

About

jv-conjugator is a powerful Japanese verb conjugator library which can provide conjugations for a wide range of verb forms and form combinations including polite forms, negative forms, auxiliary verb forms, additional て-form suffixes and colloquial short versions. The library is written purely in TypeScript and fully tested using Jest. It is designed to be consumed by TypeScript projects as it takes enums as function arguments.

Installation

npm i jv-conjugator

Usage

Two callable functions are provided, getVerbConjugation for a single conjugation, and getVerbConjugations for multiple conjugations of the same VerbInfo object.

Arguments

VerbInfo

An object of type VerbInfo.

verb: An object with string properties kana and kanji. Either one or both may be provided, but if neither are provided an error will be returned.
type: VerbType enum. Typically VerbType.Ichidan or VerbType.Godan, but if the verb is irregular find the corresponding verb in VerbType to ensure irregular conjugations are correct.

FormInfo

An object of type FormInfo.

• formName: FormName enum of primary verb conjugations. Required.
• auxFormName: AuxiliaryFormName enum of auxiliary verb conjugations. Optional.
• additional: AdditionalFormName enum of additional て-form suffix verbs. Optional.
• polite: Boolean which will give the polite form of the requested conjugation if it exists, and return Error if not. Optional, default false.
• negative: Boolean which will give the negative form of the requested conjugation if it exists, and return Error if not. Optional, default false.
• shortVer: Boolean which will give the colloquial short version of the requested conjugation if it exists, or ignore if not. Optional, default false.

If calling getVerbConjugations, provide a list[] of FormInfo instead.

For more information about FormInfo definitions, see Conjugation Details below.

Return Values

• getVerbConjugation: Returns one Result object or Error if conjugation failed.
• getVerbConjugations: Returns either Error if VerbInfo processing fails, or a list[] of Result objects and/or Error objects (if conjugation fails for a particular FormInfo).

The Result object contains string properties kana and kanji which are the corresponding conjugation results. Each property will only be defined if they were defined in the VerbInfo argument.

Example usage

import {AdditionalFormName, AuxiliaryFormName, FormInfo, FormName, Result, VerbInfo, VerbType, getVerbConjugation, getVerbConjugations} from "jv-conjugator"

const verbInfo: VerbInfo = {verb: {kana: "たべる", kanji: "食べる"}, type: VerbType.Ichidan};

const formInfo: FormInfo = {formName: FormName.Past, auxFormName: AuxiliaryFormName.Passive, polite: true, negative: true};
const res: Result | Error = getVerbConjugation(verbInfo, formInfo);
if (res instanceof Error) return;
console.log(res.kana + ", " + res.kanji);

const formInfoList: FormInfo[] = [
    {formName: FormName.Past, auxFormName: AuxiliaryFormName.Passive, polite: true, negative: true},
    {formName: FormName.Present, additionalFormName: AdditionalFormName.TeAgeru}
];
const resList: (Result | Error)[] | Error = getVerbConjugations(verbInfo, formInfoList);
if (resList instanceof Error) return;
resList.forEach(result => {
  if(result instanceof Error) return;
  console.log(result.kana + ", " + result.kanji);
});

Conjugation Details

Notes

• Any field marked N/A will return an Error, except in the case of a missing shortVer which will return the standard version.
• Additional endings such as ください or なら are left for the consumer to add, as they are not affected by conjugation themself.
• It is possible to create form combinations which are gramatically correct but make little semantic sense, which is left for the consumer to decide.
• It is possible to request any combination of FormInfo parameters, although the result may not exist.

FormName

FormName	Plain	Negative Plain	Polite	Negative Polite
Stem	し	N/A	N/A	N/A
Present	する	しない	します	しません
Past	した	しなかった	しました	しませんでした
Te	して	しなくて	しまして	しませんで
Naide	しないで	N/A	しませんで	N/A
Tai	したい	したくない	したいです	したくないです
Zu	せず	N/A	N/A	N/A
Volitional	しよう	しなかろう	しましょう	N/A
Imperative	しろ	するな	しなさい	N/A
BaConditional	すれば	N/A	しますれば、しませば (shortVer)	N/A
TaraConditional	したら	しなかったら	しましたら	しませんでしたら

AuxiliaryFormName

Note: For demonstration purposes AuxiliaryFormName is combined with FormName 'Present' here.
Note: Whether an auxiliary verb has a valid shortVer is highly dependant on the type of verb.
Note: する will return できる for the Potential form.

AuxiliaryFormName	Standard	ShortVer
Potential	食べられる	食べれる
Passive	食べられる
Causative	食べさせる	食べさす
CausativePassive	飲ませられる	飲まされる
Tagaru	食べたがる

AdditionalFormName

Note: For demonstration purposes AdditionalFormName is combined with FormName 'Present' here.

AdditionalFormName	Standard	ShortVer
Continuous	している	してる
TeAru	してある
TeOku	しておく	しとく
TeIku	していく
TeKuru	してくる
TeAgeru	してあげる
TeKureru	してくれる
TeMorau	してもらう
TeShimau	してしまう	しちゃう

Combining All

As stated, it is possible to combine forms in any combination. For example, using one of every option for 食べる:
{formName: FormName.Past, additionalFormName: AuxiliaryForm.Continuous, auxFormName: AuxiliaryFormName.Potential, polite: true, negative: true, shortVer: true}
=食べれてませんでした (despite making little real sense)