A method of providing a natural language interface for a computer-aided design (CAD) system is disclosed. The method includes displaying to the user a model display graphical user interface (GUI), a view window that displays a first view of the CAD model, and a spectrum GUI configured to allow the user to selectively add CAD-tool functionality, receiving a voice input including a plurality of words and referring to a CAD-tool functionality, parsing the voice input, determining a meaning including a reference to the CAD-tool functionality for the parsed voice input, assembling a query for additional information based on the meaning, sending the assembled query to a corresponding information location, receiving queried information from the corresponding information location, translating received information into a response, determining that the response includes a command for the spectrum GUI regarding the CAD-tool functionality, and sending the command to the spectrum GUI.
