Html5 & javascript, is it fair to say that they should be learnt in tandem?

Question

Html5 & javascript

Answer 1

If you mean that you should not learn HTML without JavaScript, no! JavaScript is a nice addition and enables many functionality, however you certainly do not need it to build a standard website (in fact, JavaScript is only really needed if you want to break out of the http request-response-cycle and fetch server data dynamically/on the fly (aka. AJAX) or do calculations without reloading. Even animations can be done with pure HTML, or CSS.
However, HTML, CSS and JavaScript are the backbones of every modern webapp (As they tend to utilize AJAX). So it is worth mastering those three.
BUT:
I personally do not enable JavaScrip on my browser by default, and imho static websites should not depend on JavaScript.

Answer 2

Thank you Felix