The present continuous tense is used to describe activities that are happening now or are in progress now, activities or situations that are currently true but not necessarily happening at the moment, and temporary activities or planned future arrangements. It is formed using the present tense of the verb "to be" and the present participle form of the main verb. Questions and negatives are formed following the typical rules. Some verbs like believe or like are usually not used in the present continuous since they describe states rather than activities, but can be used continuously to change their meaning to an activity rather than a state.