Since the seminal work of Frege and Quine we know that entities can be conceived from many different perspectives and what perspective is assumed can be relevant for our evaluation of attitude reports. For example, suppose Philip is aware that Cicero denounced Catiline but he is unaware that Tully denounced Catiline. What would be the truth value of the sentence `Philip is aware that x denounced Catiline' under the assignment that maps x to the individual which is Cicero and Tully?
In this talk I will present one solution to this and related puzzles which uses the notion of a conceptual cover and discuss two more applications of this notion to two phenomena that have received some attention in the recent linguistic literature: epistemic indefinites (indefinites which signal ignorance on the part of the speaker like German `irgendjemand') and concealed questions (nominals that behave like identity questions like `the price of milk' in `John knows the price of milk').