Modals of certainty such as must, can't, may, might and could are used to make deductions or assumptions about situations in the present. The modal verb chosen depends on the degree of certainty of what is being said. These modals are generally followed by an infinitive when referring to habitual situations or stative verbs. However, when referring to temporary situations or actions happening at the moment, they are followed by a gerund. Examples of their use include "You can't be hungry" and "Paula must be lying on the beach now."