The usage of "only" is the most commonly used, and it is this word that many people make mistakes very easily, because quadruplets look very similar. (See the picture below) There are completely different words for a little more and a little less here. If you are not careful, you will make mistakes.
Strictly speaking, a single word is not a modern simplified word. First seen in the Warring States period, it should belong to a simplified word in ancient Chinese. It was first seen in Oracle Bone Inscriptions in Shang Dynasty, meaning bird.
Only for pictophonetic characters, the original meaning is only. Therefore, in calligraphy creation, modern simplified characters and universal characters have different usages in different places. For example, Qian Shan Wanshui is just idle, and only one can be used. Never use only one. This is a big joke.