Marathon 1

(Having leg problem) After a miserable car accident when I was seven, I could not walk like (as if ) a zebra that was injured by a lion's attack (which has eventually escaped)

However, I (have inspire to walk and run to) my dream was to become a marathon runner ( which was my dream). (Now, I am 21.)

I had been practicing walking (,) and running for the past few years. It was as difficult as climbing the 'Mount Everest'. Now I (am) was ready to run the 42km marathon. My legs were trembling (like a vibration in the handphone)(1). Soon, the marathon (was) started.

(Everyone which were about) (2) Two thousand people were jogging for the first few minutes (and) but they were getting faster and faster. I had a difficulty catching up with them. (The track was filled with cheering voices.) (3) and (There was) a few people even ran like mad cows. I felt like dying very soon as (it) I was very tired.

(While running for an hour, I saw a man with a brand new suites with the cost at the back part of the shirts. It was so expensive that i could not remember the number.) (4)

There was no one infront of me. I knew I was the last and felt terrible but soon I saw a sign "1km away to the end! HURRY!!!" then my feet (was getting) felt cramped. Suddenly I thought I heard (But I saw) my family members (were) cheering very loudly (that I can even hear them) even from a few hundreds metres away.

I knew I (have) had to try my best to achieve my dream. So, I ran as fast as my legs could carry me. ( and reached in a few minutes.) When I reached the end (, they gave me the medal of finishing the 42km marathon. Although I was not the winner, i was glad that I had finished the race. ) I smiled showing my ugly teeth without shame.

Mrs Chien: Attempts at making clear observations are excellent. I can see this marathon runner working so hard and his huge smile at the end!
Now don't be fazed by the large amount of corrections:
(1) Comparisons like the injured zebra are very effective in helping the reader imagine what is happening - in the case of the trembling legs, comparison is not needed.
(2)he word 'everyone', 'everything' is not useful to the story - always be specific - spectators, runners ...
(3)This observation does not fit into this paragraph where the main idea is about how hard the runners are working.
(4) Same as (3).
Finally, continue to work hard at changing actively how you view 'compo writing' and soon you will see improvement. Next time, attempt smaller pieces of writing and focus on a few sentences at a time.