On the logical makeup of how- and why-questions

We employ wh else-phrases as a novel tool for investigating the logicalmakeup of wh-questions. Applying the wh else-diagnostic to how- and why-questions,we show that they comprise two different logical types, which differ interms of whether or not two of their Hamblin answers can be compatible. How- andwhy-questions can also be classified in grammatical or notional terms (e.g.,Higginbotham 1993, Oshima 2007, Sæbø 2016). Our findings therefore raise thequestion of how the logical typology and grammatical or notional typologies ofhow- and why-questions might be related.