The OCR engine supports spell checking through language dictionaries. You set the spell language to use with the IOcrSpellCheckManager.SpellLanguage property prior to calling IOcrPage.Recognize.
Each OCR engine supports different language dictionaries, to get a list of the dictionaries supported by a specific engine, use IOcrSpellCheckManager.GetSupportedSpellLanguages.
For more information on the spell checking system, refer to IOcrSpellCheckManager.