This guide will show you how to ask the seller regarding questions you have about an item the seller has for sale. Taobao and Tmall has a live chat system called 阿里旺旺 which allows buyers to contact sellers regarding any questions they may have about their items on sale, or to ask for refunds and solve problems regarding item status.
Navigate to the item you want to enquire about, and tap on the Contact Seller button as shown in the picture below.
When you contact the seller from an item's page, a link to the item is automatically created. Tab on the Send Item link to the seller to let the seller know about the item you want to enquire about. Sample chat lines for general enquiries can be found here.
You can type in or paste in copied text to send to the seller here.
You can also upload pictures to the seller by tapping on the plus icon. A panel with more options will pop up.
Tap on the icon marked 'a' in the picture below to use your device camera to take a picture to send to the seller, and tap on the icon marked 'b' in the picture below to open your photo gallery and upload a picture to send to the seller.