Front end developers spend a lot of time using HTML5 when they're putting together web designs and have access to a wide range of features that can save development time and improve the end product. What to look for in an answer:
In-depth knowledge of HTML5 features
Clear explanation of how the applicant used HTML5 in past projects
Creative usage of HTML5 features
Example: "I enjoy the way HTML5 handles multimedia support compared to previous versions. I use this feature to develop a front end design that incorporates videos and audio as an essential part of the experience without worrying about it not loading properly or breaking the page."