Wah How to use "Indirect Questions"

We use Indirect questions when we speak to someone we don’t know very well, or in formal situations. Indirect questions are often a little more formal and polite than direct ones. 

    Direct: Where is the post office?
    Indirect: Could you tell me where the post office is?

    Direct: Which hotel are you staying at?
    Indirect: Can I ask which hotel you are staying at?

    Direct: Who is that beautiful woman?
    Indirect: Could I ask who that beautiful woman is?

    Direct: What time does the store open?
    Indirect: Do you know what time the store opens?
    Note: We don’t use do,does or did in indirect questions  

    Direct: How much does this mobile phone cost?
    Indirect: Can I ask how much this mobile phone costs?

    Direct: Why did you resign from your job?
    Indirect: I was wondering why you resigned from your job. 
    Note: This statement is a request that ask someone to give more information, so this indirect one is not a question.

Wah How to use "How come..?"

When you want to know why something happens or you are surprise about an action, you can ask for the reason by using how come.

• How come you can speak English very well? (How can you speak English very well?)
• How come you don't like the wasabi? (Why don't you like the wasabi?)
• How come you know I hate cockroaches? (How do you know I hate cockroaches?)
• How come you left my laptop in the airport?
• How come he get here earlier than us ?

"How come you're not here?
Should I worry you've been bitten?
Or somebody got you high?
Quick come back
Or I might just die
How come you're not here?..." from How Come You're Not Here - P!nk