Translation of oppressive in Spanish

I will send you a summary of the activities from our last vacation last year, but I will be brief, so I will send only the highlights. It is best if we discuss everything, in the beginning of August.
It certainly is one of the reasons that a student from abroad is not as good in English as people who were born in America. This is an obstacle for all students and a challenge for the educational system.
It's very good that you can learn English with the help of technology (Internet), I think you'll learn quickly. Although I am now getting better, I feel the improvement. But once again I lack vocabulary.