1. A machine implemented method, the method comprising: receiving a user input by a processor executable, digital assistant at a device on a transportation vehicle; determining by the digital assistant an initial relationship between words of the user input by tagging user input words with a grammatical connotation; using a trained dataset selected from among a plurality of categories by the digital assistant to generate a constituent tree for establishing a detailed relationship between words of the user input; wherein the plurality of categories store metadata identifying actions for each of the plurality of categories that include one or more of an entertainment data category for entertainment related actions, a shopping category for shopping related actions, a crew instructions category, and a security category associated with transportation vehicle security and wherein the trained dataset is machine learned and updated based on user feedback over time; and providing a response by the digital assistant for the user input based on evaluation of the constituent tree, where the response includes performing an intended action for the user input by making an application programming interface (API) call to another device on the transportation vehicle.