Individual class teachers will send home spelling lists at the start of the year. In addition to this, teachers will send home weekly spellings which children will be tested on.
Please find below Government issued spelling lists for Years 4-6. These give a strong indication of the standard required in Upper and Lower Key Stage Two.
Here is the full Government issued guidance on spelling. This document is very detailed and used by teachers to support their teaching of spelling, however some parents might find it useful. As with any aspect of your child's learning, if you have any questions please speak to your class teacher!