When using Microsoft Word, one can, if a word is flagged as misspelt, choose to add it to an internal dictionary of words that have been misdiagnosed as wrong.
However, if one proceeds to use another form of this word, either in plural, genitive or something else, more often than not this is also
flagged as incorrect, necessitating one to add the variant to the dictionary as well.
I propose that, when a word is added, the computer also adds other likely forms of that word. If this proves too faulty, the selection of adding to the dictionary could be enhanced, with different options for "Add noun to dictionary", "Add verb to dictionary" etc..
It need not work flawlessly, but I dare say that not being told off every time I used a new form of whatever word I am using would be very convenient nevertheless.