有關英文grammar 問題

I have a sister called Grace. She is twenty one years old, She has been doing
jogging since she was thirteen years old. She is studying a Japanese course. She has acquired a good knowledge of Janpanese. On the other hand, she is not interested in environmental protection .

I have a sister. Her name is Grace. She is twenty one years old. She has been
running (jogging) since she was thirteen years old. She is studying a course in Japanese.(a Japanese course)
She has acquired knowledge in (of) Japanese. She has been ignoring environmental
protection.

Basically the grammar is correct in your writing. It will be better if you rewrite it as following.

I have a sister whose name is Grace. She is twenty one years old and has been
jogging since she was thirteen years old. She is studying a Japanese course and has acquired knowledge of Japanese. She has been ignoring environmental
protection.

寫過, 改了原意.

I have a 21-year-old sister called Grace. She has taken up jogging since she was thirteen. Now she is doing a Japanese course. She has acquired a sound knowledge of Japanese. It is a pity that she is not interested in environmental protection.

2014-03-01 09:23:40 補充：
knowledge of something
knowledge about + noun phrase
~ knowledge about the harmful effects of smoking

個人意見: 回答者過客 是對 ~ knowledge of Japanese


離家出走 = run away from home

She ran away from home at the age of thirteen.
她13 歲離家出走

~ 不是13 歲開始又離家又返家, 無停過許多次離家出走

2014-03-02 02:12:26 補充：
No offence. 知識交流
course = a series of lessons on a particular subject (usually at school/university)
course in + subject, a course in Japanese, 不是 a course of Japanese
可講 change the course of history, course 是另外解釋

study a course 覺得怪怪地, 純個人意見
通常 take/do/attend/enroll in/sign up for + course

Can you stick to ONE account id?

2014-03-01 00:33:54 補充：
It does not matter what thread title you use, it seems to me you are only interested in tenses. It is this sole concern of yours that makes your sentences very weird and unnatural.

She has been running since she was thirteenyear olds. 這句的意思是否說”她自從13歲便已離家出走”? 如果是可以這樣寫 : She has been running away sinceshe was thirteen years old. She is studying a course in Japanese.Japanese的意思(名詞)日本人或日語; (形容詞)日本(人)的或日語的。She is studying a course in Japan. 她現在在日本學一個課程。She is studying a course of Japanese. 她現在學緊一個日本語的課程。 She has acquired knowledge in Japanese.這句的意思是否說 : 她獲得知識在日本如果是, 應這樣寫 : She hasacquired knowledge in Japan.如果是說 : 她獲得知識由日本人;應這樣寫 : She has acquired knowledge fromJapanese. 這幾句英文, 並不連貫, 只可盡力理解, 希望可以幫到手。

I have a sister. Her name is Grace. She is twenty-one years old. She has been
running since she was thirteen years old. She is studying a course in Japanese.
She has acquired knowledge in Japanese. She has been ignoring environmental
protection.

句子寫得不錯,但是要留意沒寫的字,這就很好了.

I have a sister. Her name is Grace. She is twenty-one years old. She has been
running since she was thirteen years old. She is studying a course in Japanese.
She has acquired knowledge in Japanese. She has been ignoring environmental
protection. 留意你習慣地寫錯years old為year olds. 記住年齡係可數數子years係要眾數加s的(除非1歲=1 year old)，old則是形容的詞。另外留意串字。寫句的結構和編排都ok。