1. I was preparing for a meeting with my boss. OR: I prepared for a meeting with my boss. 2. Your sentence is technically correct, but it doesn't sound natural. This would be more natural: "I wrote down all the tasks my boss gave me." I added the word "down" because it is often used when referring to taking notes or writing. The "down" refers to the paper. You wrote the tasks down on paper. The word "paper" doesn't need to be added because with the word "down" the meaning of paper is already assumed knowledge. 3. I had a meeting with my colleagues at 4:00PM about the company's financial results for July. Hope this helps!