Which language do Hong Kong people speak better? English or Mandarin??

I know Cantonese(粵語) is the most widely spoken language in Hong Kong.
Many Hong Kong people speak Cantonese as their first language.

Then what is Hong Kong people's second language?
Is it English or Mandarin(Putonghua普通話)?
Which language do Hong Kong people generally speak better?

Do you think Cantonese(Used in Hong Kong and Guangdong ,China)is the most difficult language in the world?

Do you think Cantonese(Used in Hong Kong and Guangdong ,China)is the most difficult language in the world?

the chinese mandarin supposto will a language of the future,but in china just 70% speak mandarin?

i think if chinese mandarin will a 1 language to level global they need to teach the language in china because in china 30% of the people don't speak mandarin,example hong kong's people speak chinese cantones so!!! what do you think

Can I use chinese characters for my baby’s Malaysian birth certificate instead of pinyin?

I want to use my baby's English name and surname but for her chinese name, I want to write that in chinese characters instead of pinyin. Is that allowed for Malaysian birth certificates? I know it's allowed in Singapore and Hong Kong.

what is the difference between cantonese and hongkongnese (the language)?

People from Hong Kong speak Cantonese, but so do people from other parts of China. BUt what makes the Cantonese dialect from Hong Kong so different from the common Cantonese language?

PLease include slangs if available/posssible.