Its partly cultural I'm sure, but when you say English I think you first need to understand their exact problems...
Here's what I'd try and evaluate:
1. Can they follow English instructions spoken and written.
If you are not sure write the instructions on the board to test. (In English language teaching we use Concept Checking Questions CCQs)
If they can't then you'll have to teach them basic English...
2. Do they do well in grammar exercises/reading comprehension/listening comprehension?
They may have been taught basic English, but have difficulties with productive skills. (Writing and speaking)
3. Are they afraid to give an opinion? Can they communicate verbally?
They may have been taught in a system where there is always a right answer and so therefore want to learn answers by rote rather than express their own opinion.
Depending on their level, I'd suggest you try and come up with some kind of placement test (you can use the
ELT search engine on my site to try and find something suitable.)
Useful resources:
1.
Guided writing
They can follow instructions, so it doesn't intimidate as much as free-writing
2.
Argumentative writing
Requires them to think on their own.
3.
Mindmaps
Can they think creatively?
There are plenty of other resources, once you've diagnosed the problem, you can start at my Website:
http://www.jamesabela.co.uk/ which is conveniently divided into levels.
James