In understanding any topic of discussion, one very important thing is the context of the issue. Each of us has some kind of world knowledge and topic knowledge, and thus should bring them to use. For examples, if the interview is about dam building, if you know anything about this, you should use it to help you interpret and make sense of the interview you are listening to.
When speaking, you should be aware of your weak points and try to be careful. Do you have any fossilization in language use? This may result from your mother tongue. Some Thai people do not use the ending ‘–s’ because in their language they do not have them. Some Chinese are confused between ‘he’ and ‘she’. In your own language, what are your fossilizations or common mistakes?
After you practice speaking, you should then try to get some feedback. This may be from your actual conversations, i.e., response from the person you are talking to or your audience. Or you can ask your friend to give you feedback. Then you can improve your English.
You can always ask for more clarification. The following are examples of ready-made phrases or set phrases to use.
Could you please speak louder?
Could you spell that for me, please?
Could you say that again, please?