  We consider a modification of the voter model in which a set of interacting
elements (agents) can be in either of two equivalent states (A or B) or in a
third additional mixed AB state. The model is motivated by studies of language
competition dynamics, where the AB state is associated with bilingualism. We
study the ordering process and associated interface and coarsening dynamics in
regular lattices and small world networks. Agents in the AB state define the
interfaces, changing the interfacial noise driven coarsening of the voter model
to curvature driven coarsening. We argue that this change in the coarsening
mechanism is generic for perturbations of the voter model dynamics. When
interaction is through a small world network the AB agents restore coarsening,
eliminating the metastable states of the voter model. The time to reach the
absorbing state scales with system size as $\tau \sim \ln N$ to be compared
with the result $\tau \sim N$ for the voter model in a small world network.
