+0
Can I say,

On a quater past four, Sam and Peter went for their volleyball practice. They cycled hurriedly because they were late. Their volleyball practice were starting at four-twenty.

While they rode Peter lost control of his bicycle and crashed into the sand. Sam felt shocked when he saw his friend injured. Peter hurt both his legs.

Sam carried Peter on his back. He ran to the a clinic nearby. The doctor treated both of Peter's legs.

Thanks!

Comments  
Vincent, I keep meaning to ask you: Are these homework assignments, or are they stories you are inventing yourself in order to practise your English?
Dear Wordy,

Thanks for your help first. These are the few paragraphs that I tried to write. That's not my homework. LAst time, I wrote in a sentence, but the Eng expert advised me to write in a paragraph, so I try to do.

If I arised any troubles to you, I said "sorry" to you, thank you!!
Site Hint: Check out our list of pronunciation videos.
Right. I'm reluctant to correct whole passages of text if it's homework. If it isn't homework then that's fine. Nevertheless, I just highlighted the mistakes that you should be able to fix yourself. (I think that writing whole paragraphs rather than lots of isolated sentences is a good idea, by the way.)

On a quater past four, Sam and Peter went for their volleyball practice. They cycled hurriedly because they were late. Their volleyball practice were starting at four-twenty.

While ["while" is not exactly wrong, but for an instantaneous event like a crash I prefer "as"] they rode, [A comma is not mandatory here, but I prefer to use one. This is to avoid the possibility of momentarily parsing it as "While they rode Peter"] Peter lost control of his bicycle and crashed into the sand. Sam felt shocked when he saw his friend injured. Peter hurt both his legs.

Sam carried Peter on his back. He ran to the a clinic nearby. The doctor treated both of [Not really needed again. We all know that people have two legs.] Peter's legs.
I try:

At a quater past four, Sam and Peter went for their volleyball practice. They cycled hurriedly because they were late. Their volleyball practice was started / starting at four-twenty/ 4.20 pm.

As they rode, Peter lost control of his bicycle and crashed into the sand. Sam felt shocked when he saw his friend injured. Peter hurt both his legs.

Sam carried Peter on his back. He ran to the clinic nearby. The doctor treated Peter's legs.
Please help me to check again, thanks!!
Students: We have free audio pronunciation exercises.
You forgot to correct "quater".

It should be "was starting", not "was started".

Otherwise OK.
Here is my feedback, VT:
Vincent TeoAt a quarter past four, Sam and Peter went for their volleyball practice. They cycled hurriedly because they were late. Their volleyball practice was started / was starting at four-twenty/ 4:20 pm.

As they rode/While they were riding, Peter lost control of his bicycle and crashed into the sand. Sam felt shocked when he saw his friend injured. Peter hurt both his legs.

Sam carried Peter on his back. He ran to the a clinic nearby. The doctor treated Peter's legs.