A handheld electronic device includes a reduced QWERTY keyboard and is enabled with disambiguation software that is operable to disambiguate text input. In response to an ambiguous editing input at a location preceding at least a portion of an output word, the software performs one disambiguation operation with respect to the editing input and another disambiguation operation with respect to the editing input in combination with the at least portion of the output word. The results are output in order of decreasing frequency value, with the results of the one disambiguation operation having the portion of the output word appended thereto.