Check the spelling of your worksheets. When you select a worksheet you cannot use the right-click (contextual) menu to check the spelling. But you can go to Text on the menu bar and choose Check Spelling from there. This command checks for your worksheet looking for spelling mistakes. If it finds words that you know are spelled correctly but not in the dictionary, Vectorworks will show these words as misspelled. If you add these words to your dictionary, Vectorworks will use them from now on.