This article analyzes aspects of the distribution of West Flemish verbs in terms of Kayne's (1994) antisymmetry approach. The distribution of the auxiliary in the Infinitivus pro Participio (IPP) construction provides evidence for three functional heads in the lower middle field: Neg, T, and F2. The word order in the IPP construction is derived by head movement of the auxiliary and XP-movement of the IPP complement. The IPP complement moves to [Spec, FP2] to check its formal features; the finite auxiliary moves either to F2 or to a higher functional head, T or Neg; the nonfinite auxiliary remains in F2. The analysis accounts for the finite/nonfinite asymmetry in the distribution of the negative affix en. The article includes concrete proposals for the implementation of feature checking.