Continuous action: 在、着、or 在。。着
The usage of 着 vs 在 has always confused me when it comes to making up my own sentences. My impression is that 着 is often used as a background to another action:
or to just describe a "state"
It seems unnatural to say：他写着信。
What the difference between:
zhenlijiangJanuary 17, 2010, 08:51 PM
Here's a post with questions answered on how to express English tenses in Chinese including ~着 VS 在~.
It has a lot of good information, particularly the clarifications from Jiaojie 老师 that you'd want to watch out for.
Hope it covers everything you want to know.