17. A computing device comprising: at least one processor; and at least one module, operable by the at least one processor to: output, for display, a graphical keyboard comprising a plurality of keys; generate a word prefix comprising a plurality of characters, in response to detecting a first portion of a gesture at a presence-sensitive input device; in response to detecting, during the gesture, a second portion of the gesture at the presence-sensitive input device: update, based on a word in a dictionary, the word prefix to include an additional character; responsive to determining that an alignment score of the gesture matching the word prefix with the additional character does not satisfy a threshold, determine, using correction data that indicates at least one alternative word prefix that is based at least in part on a misspelling of the word in the dictionary, an alternative alignment score, wherein the alternative word prefix comprises at least a portion of the word prefix; determine, based on the alternative alignment score for the alternative word prefix, a candidate word; and output, for display, the candidate word.
20. The computing device of claim 17 , wherein the at least one module is operable by the at least one processor to: generate the alternative word prefix comprising at least a substring of the word prefix; and insert at least one placeholder value in the alternative word prefix, wherein the at least one placeholder value indicates at least one arbitrary character that is not included in one or more candidate words that are based on the alternative word prefix.