Dear Kiel
If their English is reasonably good, there is an IGCSE ESL (Cambridge). It is wholly language-based, not like the current English Language GCSE which is also hugely slanted towards literature. One of my EAL pupils who was struggling with the English Language GCSE did this with me in the Sixth form, and he said he really enjoyed it because he didn't have to worry about getting in all the things like alliteration into his writing, or analysing the language being used in texts.
He was asked to get what was then a B grade in it to count the same as a C grade GCSE. In fact, he not only did that, but he also succeeded (finally!) in getting the ordinary English Language GCSE grade C - partially I think because he felt confident that he had an alternative which he enjoyed and saw as much more relevant. Incidentally, he was also dyslexic - which was only finally officially diagnosed when he got to university.
Obviously this qualification does require a working kniowledge of English, so is not for absolute beginners. But it is a true LANGUAGE qualification, so I think is much more helpful for EAL pupils, no matter what the grade outcome is.
Hope this helps.
Ann