Hi emkoxinh

I hope your exam goes well. When it is?

Thanks for your essay. Here are a few points

Word Choice/Word Form

• Suppose → I would use something else here – maybe ‘I feel,’ or ‘In my opinion.’ Using ‘I suppose’ here gives the idea that you are being forced to think in a certain way.
• Some nations enforce many regulations upon children → some nations impose many regulations on children
  I would also change nations to ‘families’ or ‘societies.’
• For example, due to traffic law in vietnam, children under 18 years old driving motobike have to pay much money → fines?
  There are stiff fines for underage motorbike drivers in Vietnam.  OR    
  Vietnam does not allow under-18s to ride motorbikes.   OR
• illnesses such as depressed →  depression
• in addition to giving curtain rules for them, → certain(?)

Simplify

Try to express your ideas as simply as possible!

Undeniably, children, by dint of following several strict rules, can live more responsibly and avoid potantial life traps as well. Firstly, knowing that when making serious mistakes they will be undergoing punishment, children themselves have to consider carefully before acting. 

This could be rewritten as:

Clear rules make children’s lives safer. Rules also help them to consider their actions.  For example….

Here's another pair of sentences that need to be a little clearer:

Secondly, restrictions play an important part in keeping youngsters away from evil temptations. Facts have shown that no sooner do parents and teachers make light of education than children easily succumb to bad habits, say, smoking, stealing, cocaine addict,etc… 

Here's one possible rewrite:  

Some restrictions reduce temptation. If teenagers are not exposed to cigarettes or drugs, they are less likely to become addicted.

Try to avoid the vague word 'things.' Specify!

However, it seems that so strict are parents and teachers that their children may suffer mental diseases and try to do prohibited things. → 

Here's a possible rewrite. 

However, some parents are so strict that their children may rebel or become disturbed.  

Generalizations

You wrote:

African children are telling examples of those who are deprived of education and supervision, committing crime from their early life.

I hope your IELTS examiner is not from Africa! Try to avoid generalizations. This could be rewritten as

Children who are living in poverty or unable to attend school may turn to crime   OR
Poverty and poor educational backgrounds can encourage children to turn to crime.

Hi emkoxinh

Good luck in the test!

Well your teacher is right, and I am right too!

Of course you should aim to increase the types of structure you can use in writing.You definitely need a mix of short and long, simple and complex.

But in the exam, I recommend that you play safe. Don't experiment, don't try to impress too much, and instead focus on having "a majority of error free sentences" (see the IELTS Writing Task 2 Band Descriptors at http://www.ielts.org/pdf/UOBDs_WritingT2.pdf.(What band do you think that is?)

It's so pleasant to read simple well-constructed sentences without errors. Make that your first goal in the exam, not vocab or sentence length or complexity.

And in your next writing class, then feel free to try out any new structures you want!