How can I copy lessons

1. Select the lessons you want to copy. Press CTRL and click several rows if you want to copy more lessons.

2. Press Copy To button:

3. The software asks you to which classes you want to copy the selected lessons.

Note 1: if you are copying lessons without class, then the software asks you for teachers to which you the selected lessons will be copied.

Note 2: If you want to modify the lessons that are being copied a bit more, select them using CTRL and press 'Add more' button. Here you can change more then just class before the lessons are added back into the timetable. See:
Adding more lessons at once