有關英文句子問題想問問

Running is good for me. (無錯, running is an exercise or sport 跑步)

When I am running, fat in my body will loss. (錯)

1. "running" 奔跑 here is a continuing action
2. "lose" is transitive, so "fat" should be object of "lose" and "I" be the subject
3. fat in my body = my body fat
4. use present tense instead of future for facts, as "I lose my body fat"

Correction:
a. I lose my body fat when I am running. 奔跑
b. I lose my body fat when I go running. 跑步
c. l lose my body fat through running. (by means of; because of)

Sentences a,b use adverb clause to tell the condition of losing fat, while sentence c uses preposition phrase (adverb of manner) to do so.

Other examples regarding "running":
I have been running since I was 10.
Running helps burn my body fat and lose weight.
I always sweat a lot when (I am) running.
I have lost 10 pounds since I started running every day.

補充:
文法是錯
loss 是 noun, 不是 verb, lose 才是 verb
你可以講 I will lose some body fat ~ active voice
但不能說 Some body fat will lose ~ also active voice
否則 active/passive 是無什麼差別, 純是Chinese English

其次用 present continuous 是錯, it refers to 正在奔跑這段時間
用present simple 便可以

2014-11-13 02:45:34 補充：
Please ignore the following message if your primary concern is only "Grammar".

不是奔跑這段時間, body fat 便會失去
要 go running regularly and persistently (持續地)
要 healthy diet, 食太多 high-calorie foods, 跑步是無濟于事
最後 genetically, obesity 肥胖症(遺傳) 難 lose body fat

Running is good for me. - OK
When I am running, my body fat will be reduced (burnt off) .
or
my body fat will lose (not good English ) as fat will not go away by itself. It is burnt off or reduced.