A method is provided for offering auto-complete suggestions to structured search queries. The method is performed at a server system and includes receiving, from a client device, a partial search query that includes one or more search terms. The method further includes analyzing the one or more search terms of the partial search query to determine one or more auto-complete suggestions. At least one of the one or more auto-complete suggestions includes a respective predefined search operator distinct from the one or more search terms chosen from a plurality of predefined search operators based on a result of the analysis of the one or more search terms of the partial search query. The method further includes formatting, for concurrent display with the partial search query at the client device, the at least one of the one or more auto-complete suggestions that includes a predefined search operator.