1. A method comprising: receiving, by one or more processors of one or more server devices, a target text-string in a search query from a user device; identifying, by one or more processors of one or more server devices, a set of contexts, from within a corpus of contexts, that include the target text-string; determining, by one or more processors of one or more server devices, a quantity of correct spelling contexts in the set of contexts, where the correct spelling contexts include a correct spelling of the target text-string, where determining the quantity of correct spelling contexts, further comprises: identifying a number of contexts in the set of contexts in which occurrences of the target text-string are equal to or greater than a first threshold and in which a ratio of target text-string occurrences to occurrences of a reference text-string is equal to or greater than a second threshold, and determining the quantity of correct spelling contexts in the set of contexts that include a correct spelling of the target text-string based on the number of identified contexts; determining, by one or more processors of one or more server devices, a quantity of incorrect spelling contexts in the set of contexts, where the incorrect spelling contexts include an incorrect spelling of the reference text-string; determining, by one or more processors of one or more server devices, that the target text-string is a misspelling of the reference text-string based on the quantity of correct spelling contexts and the quantity of incorrect spelling contexts; and forming, by one or more processors of one or more server devices, an alternative search query in response to determining that the target text-string is a misspelling of the reference text-string.