The polite expression to.... talk, or ask a favor
when you need to ask a question, to talk something with someone or maybe ask a favor.

Mr. Sting, do you have a second /minute?
I need to talk to you about something.

Mr. Sting, sorry to bother/ interrupt you?
I need to talk to you about something.

Please give me more examples for the formal and informal situation.

thank you!

Question

The polite expression to.... talk, or ask a favor
when you need to ask a question, to talk something with someone or maybe ask a favor.

Mr. Sting, do you have a second /minute?
I need to talk to you about something.

Mr. Sting, sorry to bother/ interrupt you? 
I need to talk to you about something.

Please give me more examples for the formal and informal situation.

thank you!

Answer

Those are both great ways to get someone's attention and ask them for help.

However if you are speaking to a stranger or someone who is busy at that moment it is always good to start with an "Excuse me" or "Pardon me" if you are looking to be more polite or formal. :)

Answer

Those are both great ways to get someone's attention and ask them for help.

However if you are speaking to a stranger or someone who is busy at that moment it is always good to start with an "Excuse me" or "Pardon me" if you are looking to be more polite or formal. :)