The Present Simple tense is used to describe actions that are regular, habitual, or facts that are always true. It is formed using the base form of the verb for all subjects except for third person singular, which adds an -s or -es to the end of the verb. Negative sentences use 'do not' or 'does not' + the base form of the verb, and questions use 'do' or 'does' + the subject + the base form of the verb.