When I study the subject ... result I realized what students need to learn the language clearly. And I can take to improve their learning and teaching methods that will be used in the future.
When I study the results ... I know what the students want to learn the language clearly. And I was able to improve learning and teaching methods will be used in the future.
When I studied... As I know what students want to learn the language clearly. And I can be used to improve learning methods and teaching methods to use in the future.