1. A method implemented by one or more computing devices, the method comprising: receiving input data, the input data comprising linguistic items including: a first set of linguistic items with known intent labels, the known intent labels representing known relations between entities provided by a knowledge resource; and a second set of linguistic items without known intent labels provided by the knowledge resource; determining intents for the linguistic items in the input data to produce intent output information, the determining comprising: when a respective linguistic item corresponds to a member of the first set, deterministically assigning a respective known intent to the respective linguistic item based at least on a respective known intent label associated with the respective linguistic item; and when the respective linguistic item corresponds to a member of the second set, inferring the intent associated with the respective linguistic item based at least on selection log data; and storing the intent output information in a data store, the determining including discovering a new intent for an individual linguistic item of the second set that identifies an individual entity represented in the knowledge resource, the new intent identifying a new relation for the individual entity that is not included in the known relations provided by the knowledge resource, the selection log data reflecting actions of users associated with using various linguistic items with the known intents and with the new intent.