 The multiplicity of interpretation in these modals is pretty clear. One particularly controversial case involves imperative vs epistemic interpretations of ‘must’ as in ‘He must be here’. However, whether or not it is a lexical or structural ambiguity (or best treated as a case of univocality with indexicality) is a source of some controversy (see Drubig 2001). In the semantics literature, views on which modalities are treated indexically rather than as cases of ambiguity pretty much dominate all contemporary thinking, as we shall see in section 6.3.