Jingran indicates that the (non)occurrence of a situation that it presents contradicts the expectation, while guoran indicates that the (non)occurrence of a situation presented by it converges with the expectation. Arguing against Hsieh's (2005, 2006a, 2006b) proposal that evaluative modals in Mandarin do not have a model-theoretic semantics, I propose that, given that the expectation serves as a modal base B which an evaluative conversational background forms, jingran presents a proposition which represents a simple necessity of negation in a possible world w with respect to B, whereas guoran presents a proposition which is equivalent to a simple necessity in a possible world w with respect to B. Contrary to Hsieh's claim that modality in Mandarin has a language-specific property, i.e., that the semantics of certain modals in Mandarin cannot be defined in terms of possibility and necessity, I seek to fit modality in Mandarin into a bigger picture of modality in general and show that it is possible to achieve a universally valid notional category of modality, similar to the works of Kratzer (1981), though different languages may have language-specific choices for modal bases, which result in different types of modality in languages.