There're transcripts and/or summaries available for some videos.
You can find links to them either next to the video itself, or on a special Transcripts & summaries page, or in some cases the link is to a page that contains both video and associated text.
Introducing Emurgo - Emurgo Youtube (14 Jun 2018)
Learn more about Cardano and what Emurgo does in this short introduction video.
Cardano - Simply Explained - Savjee (8 Jan 2018)
Cardano (ADA) is gaining a lot of traction, but what makes it so special? In this video I'll explain all the problems that the Cardano team intends to solve.
Cardano | $ADA | The Blockchain Reimagined - CryptoCandor (21 Dec 2017)
Cardano is a highly secure blockchain written in Haskell. It allows formal verification of code, and easy extensibility through a layered architecture. Cardano's technology is built from peer-reviewed research at some of the world's foremost universities.
Cardano overview with Charles Hoskinson (26 Oct 2017) - IOHK
Developing Cardano is no small feat. There is no other project that has ever been built to these parameters...