Dear XX,
I konw it isn't easy to learn English,but I have some ideas that may help.You said you couldn't undersand people who taked fast,but i think it doesn't matter if don't understand everyword,and doing a lot of listening practice is also a great way to improve your speaking skills.I hope you can learn English well.
Best wishes!
Yours
XXX
这样可以吗?希望对你有帮助~~