Despite some shared properties, MSVs are a heterogeneous group, with different types of verbs exhibiting different developmental patterns.
a wealth of research shows that children produce Desire verbs, such as want and wish, earlier than Belief verbs, such as think and know (Shatz et al., 1983; Bartsch and Wellman, 1995;Asplin, 2002;Perner et al., 2003;de Villiers, 2005;Papafragou et al., 2007;Pascual et al., 2008).