We recently had a teacher leave mid-semester and now I've had to pick up the reins and start teaching his IGCSE classes. I've always avoided IGCSE but I no longer have that ootion, Lol. Anyways, half of the class has transferred in from non-English speaking schools and I am teaching English as a First Language. I'm okay with that, but the students are going to need some support materials. I found a couple of decent books that have grammar, vocabulary, comprehension, and writing activities in them (publisher is in Singapore), but I later realized that these are for supporting the GCSE English exam. My question is since the IGCSE and GCSE are both O-Level would it be okay to use these GCSE support materials for my IGCSE students? Of course I will still be teaching from the IGCSE CIE approved student book, but for extra English support materials (especially for my weaker students), would this be okay?