Is everything we learn in Year 11 a stepping stone towards Year 12 (the HSC) and will it be incorporated into the HSC?
For english, the content is practically useless, but pay attention you do the exact same kind of modules.
For mathematics, you are assessed on the content, as assumed.
For science subjects, understanding key concepts, as assumed.
For humanities, not so sure.
For languages, you are assessed on Year 11 work in the HSC (build-up subject).
Content-Specific Subjects
Subjects that tend to have specific content/modules rather than general useful things tend to only examine HSC stuff, for instance HSC chem is not going to ask you about how to recycle zinc or something or a prac you did in Year 11.
These subjects tend to have an easy to follow syllabus
Skills-based subjects
Projects that have a major project, or a performance work, such as creative arts/music/d&t obviously don't assess you on Year 11 content, generally, but assume that by studying the Year 11 content, you would have acquire useful skills/knowledge to incorporate into design/performance elements.
English is a special case, in where Year 11 is a copy of the work you do in Year 12, so learn how to master the different ways of answering the questions, and the different elements of reviewing texts for different purposes, inter-textual comparisons, critical analysis (using a range of opinions), concept/thematic studies (AOS) and understanding of choices made in the composition process (esp. Mod C)
Build-on subjects
There are two that come to mind where the content can be directly or semi-directly assessed.
Most languages (except extension subjects operate a bit differently) and Maths.