1. A method comprising: receiving, from a client system of a first user of an online social network, an unstructured text query to search for posts of the online social network, the text query comprising one or more n-grams; parsing the text query to identify one or more n-grams; searching an index of keyword phrases associated with the first user to identify one or more keyword phrases matching one or more of the n-grams of the text query, the index of keyword phrases being based on posts by one or more second users of the online social network; calculating a keyword score for each of the identified keyword phrases; generating one or more suggested queries, each suggested query comprising one or more n-grams identified from the text query and one or more identified keyword phrases having a keyword score greater than a threshold keyword score; and sending, to the client system of the first user for display in response to receiving the text query, one or more of the suggested queries to search for posts of the online social network.