How to slow down the youtube video playback speed?

Are you facing trouble to hear some particular phrases from important educational lectures on on YouTube? Our technical experts can help with the facts on slowing down the playback speed.

While watching some YouTube video many times we feel the need to see the video in slow playback speed. This could be during any scientific or technical lectures or Mathematical formulation or understanding some 'do it yourself' lessons etc.

What about the timings of the subtitles if we slow down the video speeds?

What about the audio quality in slow speed mode?