It is a common situation for me when I add new word that is similar to already existing just with article or suffix etc. That would be great if while adding word I would see similar words from list with option “reset progress”, “edit”. In that way there will be less chance of adding a duplicate.

I believe that it is not hard to implement, just search full matches for word part. E.g. I add word “an apple”, you split to tokens “an” and “apple”, throw away “an” because it is one of the stopwords. Search list for “apple” and that is it.