Within the framework of minimalist syntax, it is argued that core-syntax derivation verbs in OE and ME (up to approx. 1450) regulated by two licensing T(ense) heads (that is, T Probes) plus a v head (or Probe), all which are charge interpreting τ–features. acts as Probe v-0 (its Goal) order interpret [+/–past] τ–features for strong verbs. This capacity rely on ablaut distinction between Pret. 1...