10. The electronic device of claim 7 , wherein the replacement character is selected from among the one or more valid characters according to a value representing frequency of usage of the one or more valid characters.
7. An electronic device comprising: a memory storing instructions; and a processor executing the instructions to: detect one or more character inputs in a first character alphabet as a preceding character string, the preceding character string corresponding to one or more valid characters in a second alphabet according to a transliteration operation; detect a current character input in the first character alphabet following input of the preceding character string; determine whether the combination of the current character input with the preceding character string would result in an invalid transliteration result; and automatically perform an operation on the preceding character string to replace the preceding character string with a replacement character selected from among the one or more valid characters in the second alphabet if the combination would result in an invalid transliteration result.