There are many platforms and products that work as software-as-a-service that can likely support your needs. I've had extensive experience delivering online lessons to folks learning languages (e.g. English or French) in global environments. Feel free to reach out to me directly (email@example.com) and I can help you zero in on something that is appropriate for your needs.
Canvas is one of the newer platforms gaining a lot of adoption: http://www.instructure.com/ and is on the high end of LMS (learning management system) functionality.
Articulate is another interactive product that allows narrative and Q&A. https://www.articulate.com/
I'd need some more information to help you close in on the right choice. Is there live teaching? Are there reporting requirements to the student? To an organization? To your business? Do you need e-commerce / rights management of some kind? How often will content be updated? Who are your target learners? In what environment will the be (classroom, workplace, home). And so on.