How to compile and send SMS on Samsung mobile phone

First, the two horizontal keys of the quadruple direction key select AI in the pinyin line cursor, then press the quadruple direction key cursor down to the Chinese character line, and then the two horizontal keys of the quadruple direction key select the characters in the Chinese character line.

The big circle on the cover and the small circle in the middle are confirmation. For a great circle, pressing the top edge means the cursor is up, pressing the edge means the cursor is down, pressing the left edge means the cursor is left, and pressing the right edge means the cursor is right. This is a quadruple navigation key. It's just not marked