The Cantonese phrase "M Goi" has many meanings:
- "Excuse me"
- "Thanks" (casual)
Does it have a 普通话 equivalent? And how can I write it in pinyin? Is it even possible?
M Goi is written as 唔該 which in simplified is 唔该 or Wú gāi in pinyin.
The only thing I can think of that may be similar, although it definitely doesn't mean thanks is 劳驾 Láojià which you could use for "excuse me" or "hey" but not for thanks.
Similar to 劳驾, you could say 不好意思. It doesn't mean "Thank you" though. It can be used as "Excuse me" or "Sorry" or "Hey".