<human>: Can you provide a brief overview of the text?

Background: 20 Asian male and still new to the concept of dating. I study abroad in the UK and is friends with many international students. 

I've been turned hands down by every girl whom I approach because they don't feel comfortable by the way I approach them. They are used to the Asian "Traditional" way of dating where it's friends first then gets phone number. However, I've been so used to the western way of dating where it's talk --> if there is a spark ---> Gets phone number. 

It's like every time I ask them for their number, they automatically brand me as some sort of "player". Then it's no gold for me...where I get turned down dates after they gave me their number. In their mentality, they want to be friends first and test the waters before jumping in to anything serious. Where the western way is just about meeting people on dates to "test the waters" before heading into relationships. 

Since I've been turned down dates, there aren't any chance of "testing the waters" so the problem must be ME. It bugs me now since I have no problems speaking to girls and get their numbers but when I ask for a date/hangout then it's a no-no. 

Recently, I've sorta met a girl more and more and is attracted to her. Well, we know each other but never talk to each other in the classroom. I took it slow where I refrain myself from asking for her number because of past experience. My friend told me that she already is taken but I just wanted to know if she's using the "I already got a boyfriend" card to get out of when an awkward guy asks her out. 

So when do you guys recommend when I should ask her the question so I know that I might have a chance... and how and what way do I ask without feeling sad when she hypothetically say that she already has a boyfriend...
<bot>: Got an acquaintance to a friendship level where I'm falling for her; how do I ask her if she's available (not taken by another boy) without feeling sad if she said is she has one.