In all my Cantonese classes, I always begin with explaining the usage and distribution of function words i.e. grammatical morphemes that are essential and hence very useful for constructing a grammar, as my students can attest (please shout out if you are reading this!). In Chinese, there are a series of interrogatives (question words) that are absolutely fundamental for any student/learner of Chinese, not least because they need to learn how to form questions in Chinese. There is one interrogative that is really quite interesting and it always leads to a nice discussion between me and my mainland Chinese students. As explained before, I adopt a different teaching strategy and methodology when I teach Cantonese to native speakers of Chinese (whatever dialect, though Mandarin is clearly the most popular given its official status), since as all Chinese dialects share the same grammatical system (with different sounds), one can assume the same grammatical logic and point out the dialectal similarities and differences, which has proven to be a very effective and efficient way of teaching Cantonese to speakers of other dialects since it drastically minimizes the amount of learning. Often one finds strong parallels that are easy to memorise, but sometimes dialects use etymologically unrelated words that require complete rather than partial learning e.g. the word for ‘why?’, which is 為什麼 (weishenme) in Mandarin and it literally means ‘what (什麼）for (為)?’ In Cantonese, however, the interrogative is 點解 (dimgaai), which literally means ‘how (點) explain (解)?’ The meaning of these phrases is transparent enough but it is hard to explain this dialectal correspondence, since why and how could 點 with its original lexical meaning ‘dot’ come to be used to mean ‘how?’ in Cantonese? I was once asked to explain this by a keen student and had to think on my feet. I eventually came up with the following explanation (subsequently verified by linguistic sources): the Cantonese phrase 點解 etymologically descends from Classical Chinese 何解 ‘why?’, which means that Cantonese 點 is equivalent to Classical Chinese 何 ‘how?’ It is a very striking lexical replacement, but it is actually a very common word in colloquial Cantonese as people often say, ‘點?’ meaning ‘What do you want?’ (Probably not to be used with people whom you are not familiar with, since it is quite informal) In this usage, Cantonese 點 is exactly parallel to Mandarin 如何 ‘how’, which is the full version of Classical Chinese 何 ‘what, how?’ and is also commonly used in everyday speech as: 又如何? ‘so what?’ Indeed, a synonymous and equally common colloquial phrase in Cantonese is 又點呀? ‘so what?’, which people use all the time (again, mainly with friends rather than strangers, given its slightly pejorative tone). Funny etymology, which reveals a rather peculiar lexical correspondence between Cantonese 點 and Mandarin 如何 (< Classical Chinese 何), and this derives the etymology for Cantonese 點解 ‘why?’. Classic comparative-historical analysis. Never knew that my early days of studying Indo-European linguistics could come in so useful. Thanks to my old tutors at Oxford, Andreas (Willi), John (Penney), Philomen (Probert), Peter (Barber), Jim (Adams) and, of course, Anna (Morpurgo-Davies) (RIP).