As of Final Draft 13.2.0, FD13 has built-in autocorrect that will automatically correct common spelling errors, i.e. "teh" will be corrected to "the."
To view the autocorrect list:
Mac:
Go to Final Draft 13 in the top left of your screen in the menu bar, click Settings, and select Autocorrect from the top tabs:
PC:
Select Tools in the menu bar, select Options, and click Autocorrect from the top tabs:
To Add an Entry to the Autocorrect List:
Press the Plus (+) sign at the bottom of the list. You'll get a new empty entry on the list:
In the left-hand field, type in the misspelling you'd like replaced. In the right-hand field, type in the corrected spelling you'd like to use. Then click OK.
To Remove An Entry from the Autocorrect List:
Click the entry you'd like to remove so it's highlighted, then click the Minus (-) button at the bottom of the list. The entry will be removed.