可以用支付宝吗？

Just say the phrase while holding up your phone. You don't need complex grammar here. Point at the item you want to buy. Look the shopkeeper in the eye. Say kěyǐ yòng zhīfùbǎo ma?. They will usually point to a blue QR code. Or they might hold out a scanner. It is a seamless dance of technology and commerce. Even if your tones are a bit shaky, the sight of your phone makes it clear.

You will use this everywhere. Use it at high-end shopping malls in Shanghai. Use it at a tiny fruit stand on a street corner. Use it when paying for a taxi ride. It is perfect for restaurants when the waiter brings the check. If you see a blue logo anywhere, this is your cue. It’s the standard way to initiate a transaction.

Don't use this at the airport's international customs desk. They aren't selling anything! Avoid using it in very remote mountain villages where signal is non-existent. In those rare spots, cash is still king. Also, don't use it with friends if they are treating you to dinner. It might sound like you're rushing to pay when they want to be hospitable. Wait for the awkward 'who pays' battle to finish first!

Alipay, or zhīfùbǎo, changed China almost overnight. It turned the country into a cashless society. Even street performers and beggars sometimes have QR codes now. The 'blue' of Alipay is iconic. It represents the tech revolution of the 2010s. Using it makes you look like a savvy local rather than a confused tourist. It shows you are plugged into the digital ecosystem.

You can shorten it to just zhīfùbǎo? with a rising intonation. If you prefer the green competitor, swap it for wēixìn (WeChat). You might also hear sǎo wǒ which means 'scan me.' If you want to be extra polite, add qǐngwèn (may I ask) at the start. But in a busy shop, the short version is usually best. Efficiency is highly valued in Chinese retail culture.