Sometimes you see spelled with a other times Daoism Which of those two English letters exactly reproduces the Chinese sound instead being an approximation it?

The spelling "Daoism" is closer to the actual Chinese pronunciation.

Here's why:

* Dao (道) is pronounced with a "d" sound, similar to the English "dao" in "daoism."

* The spelling "sometimes" with an "s" instead of a "d" is simply incorrect and does not reflect the actual pronunciation of the Chinese word.

Therefore, "Daoism" is the more accurate representation of the Chinese word in English.