Duplicating or copying and pasting a slide in your Google Slides presentation can be helpful if you want to use it as a template. There are two main ways to duplicate/copy-paste a slide:
Select the slide that you want to duplicate. If you want to duplicate multiple slides, press and hold the Shift key on your keyboard and select them via the Slide Sorter on the left.
Go to Slide in the menu bar and select Duplicate slide.
You can also right-click the slide from the Slide Sorter and choose Duplicate slide.
Method #2: Copy and paste a slide
Select the slide you want to copy.
Choose Edit, then Copy. Alternatively, press Ctrl + C (on Windows) or Cmd + C (on Mac).
Next, in the Slide Sorter, select the slide that you want to paste your slide after.
Slide Sorter in Google Slides. Select Edit and click Paste. Or press Ctrl + P (on Windows) or Cmd + P (on Mac).
Your copied slide will be pasted.