Teach it English
This site provides thousands of English teaching resources which are free to use. These largely cover English Literature and Language from Key Stages 3-5, but you will also find some learning resources geared towards younger learners. Originally made by teachers, for teachers, the team are now kindly producing “parent-friendly” content and ideas for how to teach English at home.
https://www.teachitenglish.co.uk/
English Mastery
English Mastery provides English teaching resources for both Primary and Secondary students (up to and including Key Stage 3). In light of school closures caused by Coronavirus, they are producing free workbooks that will be a great help to both parents and teachers.
https://www.englishmastery.org/
The British Library
The British Library has a range of teaching resources supporting GCSE and A Level set texts (including Animal Farm and The Bell Jar) from the 20th century. They are downloadable as PDFs, and will help students in Year 10 and Year 12 stay ahead of the game!
https://www.bl.uk/20th-century-literature/teaching-resources#
Scholastic
Scholastic has created a free learn-from-home site with 20+ days of learning and activities available. These are largely project-based and could complement any work set by school!
https://classroommagazines.scholastic.com/support/learnathome.html
Pearson
Pearson offer a number of free resources on their website, including Key Stage 3 and 4 sample materials.
Twinkl
Twinkl has a great home learning hub, offering a mixture of free and paid-for resources. With new worksheets and lesson packs released on a daily basis, there will always be something to keep your child busy!
https://www.twinkl.co.uk/resources/keystage3-ks3/keystage3-ks3-english