How long does it take to learn calligraphy to write a decent work?

There is no shortcut to any art, it must be persevered, and it is wrong to get quick success and instant benefit. But after you persist for a period of time, you will see your progress and achievements. Of course, there is no standard for what a decent job is. Therefore, study patiently and hard, and you can write and write after a period of progress.