How is the currency of Taiwan referred to in Mandarin? (I'm not going to use the hanzi or even proper pinyin for some terms because I only know them from speaking as an absolute beginning learner.)

In Mainland China the currency is the "yuan" but in practice nobody calls it that. Instead they say "kwai".

I've just arrived by ferry in Taiwan from China and here the currency is the "New Taiwan Dollar".

Should I refer to it by the term "yuan", "kwai", or by an adaptation of the English word, something like "dola"?



Bonus: What about when referring to the Old Taiwan Dollar between 1946-49 or the Taiwan Yen during the time under Japanese rule?
Yes, people use ‘kuài’ in conversation, as in ‘yī qiān duō kuài’ (over 1,000 NT$).  You can also add ‘qián’ to make it clear you’re talking about amounts of money:  ‘wŭ shí kuài qián’ (50 NT$).

You might want to use ‘(xīn) tái bì’ when changing money, as in ‘qĭng gĕi wŏ tái bì’ (please give me Taiwan dollars).  I don’t know what was used in previous periods, but here are some ways to refer to other currencies:


mĕi jīn   ‘American dollars’ 
rì bì   ‘Japanese yen’
găng bì  ‘Hong Kong dollars’
yīng bàng  ‘British pounds’


These are from a Mandarin textbook put out by TLI, a language school in Taiwan.  Be careful with the tone on ‘tái’ - in some contexts this can be confused with the falling tone ‘tài’ referring to Thailand/Thai money.  But if you’re already in Taiwan, that shouldn’t be a problem.