A user/computer interface is described that employ a constrained natural language-form input. The computer employs a feedback method to reinforce a user's confidence and knowledge that the computer comprehends a query or instruction. The user interface initially parses a user's natural language-form input into a case frame. The case frame is then filtered into a goal-expression that comprises a verb and remaining syntactical portions of the input query/instruction. The system then paraphrases the goal-expression into constrained natural language-form and communicates the paraphrase to the user for confirmation that the computer system has correctly interpreted the user input. The computer also compares the goal-expression with prestored goal-expressions to determine a match and then performs an action in response to a match being found.