What is the difference between "我在 写字“ and ”我 写字”？ I have started to use Rosetta Stone on the side to practice more outside my college chinese classes. Everything is going well, but one thing has been confusing me. The Rosetta Stone program uses sentences like " wo zai xie zi " in situations in which we would say "Wo xie zi" in chinese class. Is there a difference between the two? This confuses me because I have only used "zai" when I am mentioning a location and as far as I can see, there is no particular location in these sentences. I don't think its a big deal, but I thought I should figure it out now instead of later...