Dear Mr White,
I am writing tell you a piece of good news. Last week our school hold a Spoken English Competition. I stood out in the competition and won a first place. In my view, it is your kind help which has helped me gain the achievement. During your spare time, you often spent such much time helping me with your spoken English that I made rapid progress. In the competition, I followed your advices on how to behave, which led to my success. I’m grateful to you for your help and decide that I will make up more efforts and try to make great progress in the future.
I’m looking forward to hear from you soon.
Yours sincerely,
Li Hua
小题1:writing后加to
小题2:hold改为held
小题3:a 改为the
小题4:which改为that
小题5:such 改为so
小题6:your 改为my
小题7:advices改为advice
小题8:去掉up
小题9:great改为greater
小题10:hear改为hearing
题目分析：
小题1:write to是固定用法，意思是给某人写信。
小题2:过去发生的事情，故用一般过去时。
小题3:这里是特指，故用定冠词“the”。
小题4:这里含有一个强调句，所以which改为that。
小题5:修饰副词much，用so。
小题6:句意：在你的业余时间，你经常花很多时间帮助我提高我的英语口语。所以your 改为my。
小题7:advice是不可数名词，所以advices改为advice 。
小题8:make efforts是固定用法，意思是作出努力。
小题9:前面make more efforts用的比较级，所以这里也要用比较级。
小题10:looking forward to是固定用法，意思是期待、期盼，后面接动词-ing形式。