11. A computer system, comprising: a memory storing executable instructions; a processor, when configured by the executable instructions, is operable to: provide a developer interface to define a flexible sentence syntax that controls how an application service, among multiple application services, of a social networking system expresses one or more edges in a social graph of the social networking system, wherein the edges represent one or more user actions occurring in the social networking system and wherein the multiple application services respectively correspond to different flexible sentence syntaxes; generate, on the developer interface, one or more selectable tokens associated with a sentence element type in the flexible sentence syntax; arranging at least one element position in the flexible sentence syntax including selecting at least one of the selectable tokens that is associated with a specific sentence element to incorporate in the flexible sentence syntax; and according to the flexible sentence syntax, a target sentence corresponding to a new edge in a social graph of the social networking system.
11. A computer system, comprising: a memory storing executable instructions; a processor, when configured by the executable instructions, is operable to: provide a developer interface to define a flexible sentence syntax that controls how an application service, among multiple application services, of a social networking system expresses one or more edges in a social graph of the social networking system, wherein the edges represent one or more user actions occurring in the social networking system and wherein the multiple application services respectively correspond to different flexible sentence syntaxes; generate, on the developer interface, one or more selectable tokens associated with a sentence element type in the flexible sentence syntax; arranging at least one element position in the flexible sentence syntax including selecting at least one of the selectable tokens that is associated with a specific sentence element to incorporate in the flexible sentence syntax; and according to the flexible sentence syntax, a target sentence corresponding to a new edge in a social graph of the social networking system. 17. The computer system of claim 11 , wherein the processor, when configured by the executable instructions, is operable to provide a selectable sentence aggregation option on the developer interface to include in the flexible sentence syntax and to include a summary of activities at once in aggregation according to the selectable sentence aggregation option, when selected.