When we speak in English being too direct could sound rude, so we need to soften our expressions. English needs more signals than other languages.
To sound polite in English the rule is that the more indirect you are the politer you are. There are several ways to do this:
- Indirect questions
Do you know if ...? - Would you mind ...+ -ing?
- I was wondering if...
- Negative statement + question tag
You aren't free tomorrow, are you? - Adding "by any chance"
Is there any chance you could ...?
Do you happen to know ... by any chance?
Expressions we can use
- Sorry to bother you ...
Sorry to bother you, but would you mind moving your bag? - I don't suppose ...
I don’t suppose you’d be willing to take me to the airport?
I don’t suppose you know her phone number, do you? - You might want ...
You might want to set an alarm next time - ... when you have the chance
I'd really appreciate your calling me back when you have a chance - I'd appreciate it if you could ...
I'd appreciate it if you could willingly cooperate with me - You don't happen to know ... , do you?
You don't happen to know where he is? - I was hoping you could...
I was hoping you could give me the name of the owner
We can use the following expressions when what follows is not going to be positive.
- I'm afraid ...
I'm afraid I can't help you - To be honest ...
To be honest the house is not quite our style - Frankly, ...
Frankly, Susan, this question of your loan is beginning to worry me
To understand it better you can see an explanation in this video How to get what you want: 5 Levels of Politeness in English