1. Good. 2. Every Friday FRIDAY, the ground is covered with people SINGING with glee. (“The ground has lots” sounds unnatural) 3. We had TAKEN three days to REACH the peak of THE ridge. 4. Good. 5. Good. 6. HIS not his’s. 7. I’m not sure what you mean by “billow” here, but billow should probably be plural BILLOWS because it follows the plural adjective “many”.