FigureInitial expectationOutcome
Praise resembling blameA fault seems imminentMore praise
Blame resembling praiseA virtue seems imminentMore censure
Particles such as «غير أن» or «إلا» can occur in both. The distinction is not the particle alone, but the semantic direction of expectation and outcome.
The syntactic construction may have its own grammatical analysis; rhetoric focuses on the effect created when expectation is overturned.