Don't give up on these kids who can't read and write.
I had one student who at the start of grade 5 was regularly ranked 2nd lowest in the grade in English,
she even flunked the listening tests. Her average scores were about 15%.
She didn't know phonics or even the names of all the letters and had no idea what was going on in class.
Anyway, now she's halfway through year 6, and dropped in to my classroom after school to tell me her result on the national test :
80%!

Plus, she can do all four skills confidently and is now in the top third of the class.
So it can be done! The elementary school curriculum is not insurmountable, and if you've got kids who are way behind, just
be patient, be stubborn and keep working with them. If anyone tells you that "they can't do it" or "you're wasting your time
with that one", ignore them. Anyone can learn a language if they put the work in.