Now that you know how to translate Google Docs and PDFs, you may wonder how do I translate a slide presentation (Google Slides or Powerpoint).
An add-on to Google Slides called Slide Translator is available. This add-on will allow you to translate each individual text box in your presentation. One by one. Slide by slide. Oh, did I mention that the text is translated but not installed into the presentation? You have to do that yourself. It sounds great in theory, but the execution of the app is not there.
Alternatively, you can download your Google Slide or Microsoft Powerpoint presentation as a PDF. Then upload it to Google Drive. Then go through the steps in my last blog entry "Translating a PDF using Google Docs" to create a translated copy of the text.
It's not a perfect solution. You may lose some formatting and/or pictures. However, all of the text will be translated in one step. Much less work than using the Slide Translator add-on.
Copied from Kathleen Grace's Blog