Basically this question and this one but for Asia and Oceania.
For most of my travel, I've decided upon the destination, and then decided whether or not to learn the language. However, I'm currently wondering if there's any languages that'd be useful for multiple destinations.
I have a suspicion that Asia has fewer languages useful in multiple countries compared to Africa or the Americas.
Criteria:
- Number of countries involved, rather than population of the country. Yes, even countries you can buy on eBay.
- Distinctness of countries: Some languages spill over a bit into neighbouring countries, such as Mongolia being spoken in the neighbouring bits of Russia and China. But I'm ideally looking for languages that are spoken in countries that don't border each other, and don't have a similar culture.
- Ideally relatively easy for tourist-level communication. Some language difficulties are only for those wanting to be fluent, such as learning keigo in Japanese, whereas languages being tonal is a problem that'd affect those wanting beginner-level speaking.
- Languages likely to be taught in Australia are preferable.
- I'm more interested in countries close to Australia that are suitable for tourism, but anything east of the middle east, and not part of the Americas, will be considered for Asia and Oceania.
The languages I can think of are English, Chinese (China, Hong Kong, Macau, Taiwan), Russian (Russia and the 'stans, plus areas outside the scope of this question) and Korean (South Korea, not sure about North Korea). I can think of one or two countries that can speak French, Spanish or Portuguese, but not a huge number.
Wikivoyage's guide to Asia mainly talks about indigenous languages, rather than the ones actually used, and Oceania doesn't have a "talk" section.