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{verb}

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 with our Test Conjugation API – for free.

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

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

Further limits of the Test API:
The Test 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.

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 unlimited 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 for pricing and license conditions.
The prices for the API start at 9 €/month (max. 1 query per second)

Demo based on the API

The conjugation tool is based on the paid Conjugation API. Therefore you can test manually which verbs are in before purchasing the API.

Other language APIs by linguatools: