I thinks it’s that old chestnut of what works for SEN is good practice for everyone!
Is there one additional language or many? I noticed that Pakistani origin learners often make the same mistakes and it is possible to build sonething around this as part of basic classroom differentiation (“oh yes – class A always say x instead of y”) – but not so easy if mother tongues are many. I’ve also used Word Detectives that teaches (Latin) word roots for y3 up which is very good for both spelling and understanding word families and of course tenses, plurals etc