1. A computer implemented method, comprising: receiving a current query including a plurality of current query terms; determining, based on one or more of the current query terms, that the current query is indicative of an intent of a user to refine a query; determining a previous query associated with the current query, the previous query including a plurality of previous query terms and issued prior to the current query by at least one of a computing device and the user that issued the current query; determining a modification n-gram based on one or more of the current query terms; generating modifications of the previous query that each include the modification n-gram substituted for one or more of the previous query terms; identifying, for each modification of multiple of the modifications: a popularity measure, wherein the popularity measure is indicative of the popularity of the modification; and a related concept measure, wherein the related concept measure is indicative of a likelihood of co-occurrence, in one or more documents, of the modification n-gram and the one or more previous query terms replaced by the modification n-gram in the modification; determining a ranking for each of the multiple of the modifications, wherein the ranking of the modification is based on the popularity measure for the modification and the related concept measure of the modification; and selecting one modification of the modifications when the ranking of the one modification is more prominent than at least the rankings of the other modifications, wherein the one modification includes the modification n-gram and includes at least one of the previous query terms; and submitting the selected one modification to a query system as a submission query for the current query of the user.