21. A computing device comprising at least one processor, wherein the at least one processor is configured to: output for display a graphical keyboard comprising a plurality of keys; receive an indication of a gesture detected at a presence-sensitive input device; determine an alignment score that is based at least in part on a word prefix and an alignment point traversed by the gesture, wherein the alignment score represents a probability that the alignment point indicates a key of the plurality of keys; determine, based at least in part on the alignment score, that at least a portion of the word prefix matches correction data, wherein the correction data indicates one or more alternative characters that are based at least in part on one or more misspellings of at least one word in a vocabulary; responsive to determining that the alignment score fails to satisfy a threshold, determine, based at least in part on the at least the portion of the word prefix matching the correction data, at least one alternative word prefix comprising at least a portion of the word prefix and at least one alternative character; determine an alternative alignment score that is based at least in part on the at least one alternative word prefix, wherein the alternative character is not based on a distance that the alignment point is away from a neighboring key that is associated with the alternative character; and output for display, and based at least in part on the alternative alignment score, a candidate word.
21. A computing device comprising at least one processor, wherein the at least one processor is configured to: output for display a graphical keyboard comprising a plurality of keys; receive an indication of a gesture detected at a presence-sensitive input device; determine an alignment score that is based at least in part on a word prefix and an alignment point traversed by the gesture, wherein the alignment score represents a probability that the alignment point indicates a key of the plurality of keys; determine, based at least in part on the alignment score, that at least a portion of the word prefix matches correction data, wherein the correction data indicates one or more alternative characters that are based at least in part on one or more misspellings of at least one word in a vocabulary; responsive to determining that the alignment score fails to satisfy a threshold, determine, based at least in part on the at least the portion of the word prefix matching the correction data, at least one alternative word prefix comprising at least a portion of the word prefix and at least one alternative character; determine an alternative alignment score that is based at least in part on the at least one alternative word prefix, wherein the alternative character is not based on a distance that the alignment point is away from a neighboring key that is associated with the alternative character; and output for display, and based at least in part on the alternative alignment score, a candidate word. 25. The computing device of claim 21 , wherein the word prefix includes a first substring and a second substring, wherein the at least one processor is configured to: determine a transposition of the second substring, wherein character positions of at least two characters of the second substring are transposed in the transposition, wherein the at least one alternative character is included in the transposition, wherein the alternative word prefix comprises at least the transposition.