The current study explores the Hijazi Arabic elements b- and raaħ when used as irrealis mood markers expressing counterfactual and/or hypothetical meanings. Such meanings are coded in different languages by past and present tense morphology, i.e., by perfective and imperfective forms that are associated with some grammatical elements. These grammatical elements include some mood markers that have been grammaticalized through the "cline of grammaticality". For instance, b- and raaħ have been grammaticalized in several Arabic varieties to serve as either future tense markers or irrealis mood markers. In light of this, the paper investigates b- and raaħ as mood markers from a generative perspective and argues that they are projected in CnMP when functioning as irrealis markers and into FutP when functioning as future tense markers. The resulting linear representation is CP -> TP -> FutP/CnMP -> AspP -> AktP -> Tax-AspP -> VP.