In forming the intensive aorist, Amazigh varieties resort to a vowel augmentation. Both the site of the epenthetic vowel and its quality are quite predictable: (i) the vowel appears prefinally, and (ii) it defaults to a if it does not copy a root vowel. Couched in Parallel Optimality Theory, the paper argues that augmentation applies only when needed to augment the stem to a LH succession of syllables- an Iambic foot. It crucially fails to apply to bases with a prefinal or final vowel. Regarding epenthesis, it is driven by markedness considerations. In the default strategy, the least marked vowel, viz. a, is epenthesized. In the copying strategy, the epenthetic vowel and the radical one share features, which results in less markedness than the default strategy.