Engelska skolan i Lund?

Hi, My son who is currently going to bladins got a place in IES lund. I would like to ask few questions around the Swedish part. We not being Swedish natives and then not getting a chance to learn swedish as a native language our kids are not that good in swedish either. In bladins they do not put a lot of effort is Swedish language how is it in IES? My fear is that if it is the similar case in IES as well, then my son will have to go to grund skola prior to gymnasium. can someone please guide us in the regard.