These are some of the best summer activities you can find to keep your English alive. All of them are focused on ESL Primary Education.
You can visit the following online resources and practise your English while having a good time:
All kind of resources for all levels
Activities to practise vocabulary and verbal structures around abilities, jobs, countries, films, sports, the weekend, famous people, etc.
Resources for writing your own book in English around festivities and free time activities. Take advantage of your holidays!
Songs in English
Poems to read and listen
Stories to read and listen for all levels
If you like to explore about some of your favourite themes, try these ones:
Dinosaurs
Mammals
Volcanoes
Rainforests
Astronomy
Don't forget to use your English as often as possible during your holidays: meet new foreign friends and simply say "Hello! What's your name?", watch TV and films in English (you can use subtitles) or invent a theatre play with your friends in English...
Use your imagination!
Enjoy your holidays!