The social, discursive practice of othering in violent extremist discourse serves to present outgroups as distant yet real threats to the ideological and physical territories of an ingroup which a terrorist claims to represent. However, the role of grammatical choices (namely, non/transactive construction, voice, and mood) in enacting the othering act within the context of radicalisation to terrorism remains to be empirically verified. This paper explores the patterning and pragmatic functions—namely in framing situations, coercing into violence, and legitimising hostile actions against Others—of the syntactic structure of the othering utterances. The othering utterances, as realized in a set of eight public statements produced by former al-Qaeda leader, Osama bin Laden, were sorted manually and analysed qualitatively to help understand and showcase how grammar was strategically leveraged in the process of radicalisation. Results show that the act of othering in the dataset operates within the victimization and injustice frameworks to morally sanction antagonism and aggression via: (i) overt othering, where transactive construction, only declarative mood and active voice are used, and (ii) covert othering, in which nontransactive construction, any mood type, and passive voice are utilized. Overt othering foregrounds, through assertions and statements of presumed facts, the negative agentive role of Others and the diagnostic framing of the causal relationships between Others and negative experiences. Covert othering backgrounds this agentive role to place prominence on immoral actions and to serve in the motivational function of framing. The grammatical patterns provide evidence of the strategic character of OBL’s verbal aggression and how different mood types tend to construct the directive, illocutionary point of the utterances and to enact prognostic framing. The analytical strategy aids in threat assessment and preventing radicalisation by sensitizing assessors to, first, the kind of semiotic clues to engagement in the social and discursive process of radicalisation where utterances count as calls for action and activators of a reality of deontology, and, second, to the social functioning of terrorist texts in: (i) promoting putative readers’ awareness of particular outgroups, and (ii) ideological positioning and encouraging and legitimating violence that is liberty, loyalty and care metavalues-based.