Auto Correct stores a list of common typographical errors and their spellings. When you make an error, Word detects it and inserts the correctly spelled version of the word. You can add words to the AutoCorrect list, based on the mistakes you make. Look at the AutoCorrect dialog box.
Note: that tm within parenthesis is automatically replaced by ™ with trademark symbol. To Add an AutoCorrect
Click Tools then click AutoCorrect, type the word in the place provided for Replace and With Options then click Add and then click OK. You can Delete an AutoCorrect option if you don’t want it.