有0的英文文法唔明

He lives with Tom boldly just to prevent him from hurting others.
我害怕自己沒有足夠的勇氣( present)
lived ( past)
to prevent 防止 someone from doing something<-----------
I am afraid that I don't have enough courage.( present)
was didn't ( If you want to talk about the past)
Most of the pictures are about him playing ( something or with xxxx).

It is almost night at that time . <===========ok
It was ( past tense then)
5)They need to be quick .<-----------ok( present)
needed ( past)
6)He will kill them if it is night .
如果是晚上,他就會殺他們
When night falls, he will kill them( all). Use" when"
另外,我仲想問寫book report,內容撮要要用咩tense?如果0係comment裡寫返0的書內的內容,又要用咩tense呢?
Present tense and past tense mainly
Check out the websites below and you will find your answer there.
http://www.teachervision.fen.com/writing/writing-composition/2030.html?_R=1
http://www.howtodothings.com/hobbies/a4110-how-to-write-a-book-report.html

I read this book called 'Thomas Jefferson's Life' and I learned a lot about him. Thomas Jefferson was our third president and he helped write the Declaration of Independence. The book said he was born in Virginia..." ( past tense )
Before I read this book, I thought Mexico was a desert island far away, but now I know it's an exciting place to visit, with lots of things to do. I can't wait to read another book about different countries." ( past tense and present tense )

just want to give some opinions.

2)I would afraid I did not have enough courage.

唔洗用would, 而且afraid 係adjective, 所以要加verb to be

這個或許會比較好 "I'm afraid that i do not have enough courage."