I am writing a summary for last year and I have just realized that I do not know what tense to use in the following situation: Since 2009 I have been developing a computer program. As I am describing what I was working on last year, what tense should I use? I think I cannot use simple past tense because I am still working on that. I also think I cannot use present perfect because the description will relate to period of time that passed. Could anyone help me on this? Thank you
If your summary focuses on what happened in 2011, but you are still working on the computer program now, then you could write something like this: "I continued working on the computer program which I started developing in 2009."
That looks right to me, you're using the present perfect continuous tense. I would move since 2009 to the end of the sentence though: I have been developing a computer program since 2009 feels more natural to me.