you writing structure is quit messy so I have rewrite most of them with a simialr meaning

subject:申请奖学金相关事项(I am not sure if this is a email. if not you no need to put a title at the beginning)
敬启者( Dear Sir/Madam)
您好， 我是Denis(you need to self-intro frist as chinese writing is a bit different e.g I am Denis,I am a .....)感谢您授予我这一个学期的奖学金。 因为我过往只有申请一个学期的奖学金，故特意来函垂询。<since you are writing a formal letter you tone wont seems like talking with a friend, so I help you correct the beginning as a more formal way. the sentence meaning is similar like I am writing to ask about the application of scholarship>

     为什么我之前不申请为一个年期的奖学金的理由是因為想我原本以为可以先申请为一个星期的奖学金，然后再申请。加上我对在上海生活有点迷茫,所以当时没有很坚定地申请一个年期的奖学金(I have change it to:I felt confuse about living in China,so I didnt apply the whole year schoolarship confirmedly) 。但是自从来到了中国后，我发现我真的很喜欢中国。我特別喜欢待在上海，因为这里有很多美丽的地方。我也去过杭州和乌镇，我在哪里度过了一段美好的时光。（Aftering I came to china, I realized I really love this place, especially Shanghai,there are so many beautiful place for me to explore  and also the cities close to Shanghai(Hangzhou, Wuzhen)但是很遗憾的是，如果我不成功申请下一个学期奖学金，这个星期後我就不得不回英國。我知道这是我的过错，我应该申请为一个年期的奖学金。（However, unfortunately=遗憾 I have to go back to uk if I cant sucessfully apply the schoolarship. I understand that this is my fault. I should apply the whole year schoolarship. )

       我在中国度过了一段很愉快的回忆。我希望申请多一个学期的奖学金的理由，是因为我想留在这里去探讨汉语的美。汉语是一种美丽又高深的语言，虽然在这一段日子里我提高了中文的水平，我相信我的水平仍大有不足之处。我还有很多地方要去了解中国的文化。在未来，我希望能够在中国进修博士课程，基于在中国进修博士课程要具备一定水平的中文能力，我十分希望能够待在充满文化气息的中国学习，我认为哪儿都没有比在中国的这样的环境去学习更好，因为这里有着最好的老师去让我在他们身上学习。（I have a great time in here. I hope I can apply  one more semester of schoolarship to stay here. It is beacuse I want to stay here and discover the beauty of Chinese Language( I know you didnt mean to say like this but normally these kind of application we will say something good so as to let the that person more willing to give us what we want). Chinese is a beautiful language and hard to learn, though i have improved my chi language, I believe my standard is not enough. I still have so many things need to learn. In the coming future, I want to seek for PhD degree. As PHD required a high lv in chi language.I really hope I can stay in such environment to learn as I believe there is no better way than learn in a Chinese environment from the great teachers.)

      正是基于以上事实，为了提升我的中文水平，为了将来能够回报社会。我郑重向学校申请多一个学期的奖学金。虽然知道我的申请有点迟，但仍希望学校能批准申请。如果学校能给予我这个机会，将会是一个莫大的鼓励，必将激励我今后更加努力。十分感谢。(USE BEAUTIFUL WORDS TO PSISON THEIR MIND :)=As those reason I have mentioned, in order to improve my chi and make contribution to the society. I am here to apply solemnly(actually i m not sure it this the right eng). I do understand that my request is  late, but I still hope the school can pass my application. If you give me a chance, it will be  a great honor and encourage me to go forward.Thank you.REMEMBER WRITING THIS KIND OF LETTER YOU HAVE TO USE BEAUTIFUL WORDS!)

     敬祝

安康（>this is a chinese formal you have to said something like Best regards and Good health <those stuffs)

详情:申请单编号：CISALTUB1505620( you wont said my detail. Detail is enough)

                                                                                                      ^...Denis Molofej敬上

(what is ur identity you have to add like year one student denis Molofej敬上)

                                                                                                              Date

Remember in chi formal the ending write on the right side.

电子邮件向扩大奖学金

您好，

感谢您授予我(这）一个学期的奖学金。

我想问（请问will be more polite)您,如果能够扩展它多了一个学期？ (要如何多申请一个学期的奖学金?>1.如果 means if 2. 奖学金通常不会用“扩展”来说)

理由为什么我不申请为一个年奖学金（为什么我之前(=before)不申请为一个年(期的)奖学金的理由是因為）想我（原本想=I decided to ... at first）可以申请为一个星期(的）奖学金然后扩大它。还有我担心在上海我生活是。。（what do you want to mentionhere? if this is a formal letter,you better talk about it)但是我实现(发现>实现means achieve a goal or something else)我很喜欢中国,但是(如果)不可以(成功=sucessfully會比較好)扩大(申请）奖学金所以以后这个星期我会得回英国（这个星期後我就不得不回英國>这个星期我会得回英国means This week, I will go back to UK.不得不means have to)。我同意这是我的错误，我应该申请为宜(一）个年（期的)奖学金。 

我真爱等(等means wait If you want to say "stay" it should be 待在上海or留在上海）在上海，我（喜歡=like)去关于(关于means about)漂亮的地方。我也参观(过if you add 过=参观过means you have been to ...already)杭州，(和same as English you will say apple and orange instead of apple, orange )乌镇。我有了好好时间(this is quite weird because it means I have a good good time. If you wanna say you have spend a greate or wonderful time there. you should say我在哪里度过了一段美好的时光) 。我有只
(一段)愉快的回忆关于中国。

我理由我想要申请一个都星期(do you want to say you want to apply for one more week or a year?我想要申请多一个星期(星期means week))。我觉得我提高了中文(的水平）但是我还没（能夠）流利（的使用）>means I still cant fluently speak Chinese. 还有在未来。，我还没有（了解）很多事情关于中国的文化，菜（食物means food菜is also same but kind like not so formal)，(還有）地方。我在中国想申请学习博士。如果我可以等一个多(多一个)星期我可以(就）实现这个目标。我认为哪儿（都）没有更好的办法比学习在中国的环境，（if you want to say" There do not have any place better to learn instead of the environment here=我认为哪儿（都）没有比中国的学习环境更好的办法地方=place），学习从好的老师。 （if you mean" learn from the best teacher=  从最好的老师身上学习）

我明白我（的）询问（询问means ask= 发问(noun))听(听means hear)（有点=a bit)晚了。但是要是您可以帮我，我会感谢您(的）。 

我的 详情:申请单编号：CISALTUB1505620

诚挚，

Denis Molofej

我在香港开始每週一次写汉语的小作文

大家好！这(一）年我移居香港了。因为我的家没有（因特网联通x）連上網絡，所以我不可以（上網）练习汉语！这星期我给PPCW（我記得是PCCW)(我的(服务提供商x)電訊公司）打电话了。他在我的家（设置因特网联通x）安裝網絡（網絡用設置感覺怪怪的）。我近来很忙，

但是我知道通过写博文，我练习汉语，<兩句斷開聽上去會不順>但是我知道通過寫博文可以練習漢語

（去）提高我的汉语水平。因为（由於>會比較好你用太多因為了)我在香港生活(，)我经常(只需要)用英语和粤语, 从未用普通话(普通話不太用得到)。还有我女朋友不会说普通话。。。其实她懂普通话，但是她不想用，宁可用粤语。所以我得自己学习，自己激励(自我激勵）。

我要每週一次写汉语的小作文。激励我！ （發奮圖強=决心努力）

谢谢，
亚当

Hello I am a Hong Kong student who can speak mandrain and cantonese fluently. I am finding someone who can improve my English as well.:)

I prefer you to learn mandrin first. Since cantonese is much more harder to pronoun. After you have learnt mandrain,  you will find easier to pick up cantonese. ( not kidding: My friend from tanwai who speak mandrin only, he came hong kong for half year only then he learnt how to speak cantonese. He say learning cantonese will be much more easier if you know mandrain and you need to talk to the local.