The book considers the grounding problem for natural language sentences in form of modal conditionals. The modality is encoded in a form of the three modal operators of: possibility, belief and knowledge. It is assumed the meaning of conditionals should be anchored in the subjective and incomplete knowledge of the speaker (the cognitive agent). According to this assumption an original model realizing the grounding of conditionals is presented. Conventional semantics are defined for various formulas representing different modal conditionals are defined within the model. The semantics include...