 Proponents of the cross-linguistic argument might challenge Logical Form: the different ways of ascribing knowledge-how (through the infinitival form and through the interrogative form) in these languages indicate that knowledge-how ascriptions in English are ambiguous between two not truth-conditionally equivalent logical forms: an interrogative form and a bare infinitival form (Ambiguity Hypothesis) (Rumfitt 2003; Wiggins 2012; Setiya 2012; Glick 2012; Ditter 2016; Hornsby 2016). The main piece of evidence for the Ambiguity Hypothesis is that in languages employing both the interrogative form and the infinitival form, those different ascriptions can come apart in their truth conditions. For example, it is claimed that the Italian sentence “Mario sa come nuotare” (interrogative form = “Mario knows how to swim”) may be usedly true, while the sentence “Mario sa nuotare” (infinitival form = Mario knows to swim) is false. This would be the case, for example, if Mario lacks (in some sense) the ability to swim (so too for its French and Spanish translations). Similarly, Ditter argues that in Russian, the interrogative construction must ascribe a different state from the “umetj” ascription (+ infinitival), on the ground that one can coherently use in Russian sentences of the following form: