These 18th century documents do not always conform to modern spelling rules, which can make searching difficult. You might not think of spellings like "nabor" or "afeckshonat" or "prittey."
If you check the box marked "sounds like" the search will be more lenient about exact matches, but this is no guarantee that you will always find what you want.
We have been compiling a list of variant spellings in the Franklin papers, and we plan to use this list to improve our searching in the future.