So 5 years ago, a user called Master-of-GTA released a mod called GTA3 Spellcheck. He basically corrected some of the grammatical errors that Rockstar North left within the american.gxt file of GTA3. Unfortunately he was banned from GTANet sometime back, and only got as far as correcting the missions up to 'Luigi's Girls'.
What I wanted to do was basically finish what he started, and spellcheck the rest of the missions. I basically took a text editor, went through every single line of text within american.gxt, spellchecked the ones that had errors, and now I believe I have something suitable for people who like to play GTA3 with subtitles but didn't appreciate the errors Rockstar left.
Version 4 Uploaded! Version 4 of GTAIII Spellcheck has been uploaded, with Catalina's lines in the final story mission The Exchange corrected. Now awaiting GTAGarage's approval. Also, version 3 of GTA3 Spellcheck has been removed. So sorry for the frequent updates, but hopefully this will be the last one for a while.