Pardon Me

" pardon me" is mostly used in UK, though it is a popular and highly polite in tone, "pardon" comes from French and the phrase is not informal.

In USA frequently is used "I'm sorry", "excuse me".

generally, i think the saying "i am sorry" is more common and direct so most people use it in, especially in HK.

"pardon me" is more polite way of expressing an apology. Foreigners use the term more.

pardon me係原諒我,一般都係用i beg your pardon

Pardon me, sorry and excuse me. 都係"唔好意思" o甘解

"Pardon me" or "Pardon" is formal English. i.e. The written way. And it is British English. Some Austrlians may also use it.
However, usually in oral English, British, particularly young British, and also Americans would say "Excuse me!", "Can you repeat it?" or "Please say again."

呢個係英文用語黎架，其實個意思有少少指自己聽唔清楚，想對方澄清一次咁。