A book teaching Finnish for school children tells on page 11: “It is important to know the infinitive, if you need to look up the word in a dictionary. You can get help in this at verbix.com that recognizes the conjugated verb form and returns the infinitive”.
The feature of finding the infinitive is available for many languages. More than this, you don’t even need to know the language of the entered verb form but Verbix will find it out.
Links:
- Verbix Verb Finder
- See what Verbix finds about ‘taught‘