For me personally, it depends on the day. Sometimes I'm very busy and have a lot of homework, so I would hang out by myself to get my assignments done as quick as possible. If my friends were there, I would get distracted, and the assignments would take longer to get done and won't be the best quality. Sometimes, I have no homework, and I would spend that time with my friends after school. It's good to spend time with them once in a while because it strengthens your bonds, and you get to experience new things together. Would I rather spend time by myself or with friends after school? With myself if I'm busy but most definitely with my friends if I'm free.
Hope this helped you come up with ideas on what to write about!
