Linguatools Conjugation API


The Conjugation API looks up a word in a dictionary and returns all conjugated forms with the associated English tenses.

The forms cover all combinations of present, past, and future with progressive and perfect tense, for each of indicative, conditional, and even passive voice.

Additionally, the infinitive with „to“, simple past, and past participle forms are returned for each verb (e.g. „to take“, „took“, „taken“).

How to use Linguatools Conjugation API

Connect to API

Endpoint and Parameters


parameter description parameter value
verb any English verb (case insensitive) e.g. change, changed, reach out

Test the API

You can test the API and develop your own application – for free, with

  1. our Test Conjugation API on Heroku OR
  2. after sign up in RapidAPI  

1. Heroku

Try out the Test Conjugation API for example with the verb change:

Important note (!):
The initial Test Conjugation API call might take up to 30 seconds because the heroku dyno falls asleep after 30 minutes of inactivity. (The Test Conjugation API runs on a free heroku dyno.)

Further limits of the Test Conjugation API:
The Test Conjugation API contains only a subset of all English verbs. Only 1200 English infinitives are included in the Test API. The paid API (see below) contains more than 11,000 infinitives.

2. RapidAPI

Advantage: Access to the full dictionary database (with limited requests, see section ‚Pricing‘)

Connect on RapidAPI

API response

If successful, the response JSON object contains the three keys result, conjugated_forms, and conjugation_tables. The key result has the value „OK“:

The conjugated_forms key has as value an array containing the infinitive with „to“, simple past, and past participle forms of the verb (e.g. „to take“, „took“, „taken“).

The conjugation_tables key contains an object with the conjugations for all tenses, split into conditional, indicative, and passive.

If not successful, the response object contains only the result key with an error message as value:

The following shows a complete JSON response object for the verb „change“:

Code snippets




Licencing Conditions

The API/data package can be used in any number of private and commercial projects of the purchaser:
E. g. in a website application, in a smartphone app etc.

Redistribution is not allowed.

If you want to use the API/data package in your project please contact
The prices for the API start at 0 € per month for the BASIC plan.


Connect on RapidAPI

Demo based on the API

The conjugation tool is based on the Conjugation API. You can use it to test manually which verbs are in the database.

Other language APIs by linguatools: