If a video does not play continuously, it may be due to your connection speed. You'll need a broadband connection with at least 5000+ Kbps upload speed and 1000+ Kbps download speed for the best viewing and uploading experience. Go to: http://www.speedtest.net/ to check your speed and compatibility.
It's also possible that TeacherTube servers are experiencing high traffic, which sometimes affects the speed. If this is the case, there's not much you can do, but we are continuously adding server space to keep up with demand. Thanks for your patience with us as we continue to grow.