It would be nice to have the words automatically lemmatised (turning inflected words into their base form, e.g. “learnt” → “learn” or “shaking” → “shake”) so that learners can learn the base word rather than having to learn from the inflected word. This can be done by using an NLP library which usually has this as a feature.
This is mostly an issue also because users are currently unable to edit word additions, so learners who would prefer to have only the base words in their saved words are unable to edit the words to reflect that. It would be good to have this feature in conjunction with the feature suggested above also as a fallback in case the NLP lemmatiser gets it wrong.