Hello Mosalla

A couple of suggestions on your essay on parents as teachers: try to simplify some sentences, and try to keep sentences short. 

Simplify and specify

However, others take an issue on this statement and they emphasis on (emphasize)the limitation of their help.

Would this sentence be clearer? It's more specific

However, other parents disagree with doing schoolwork with their children and believe that there are limits to what parents can teach their children.

You wrote:

In psychological point of view, the effects of these conflicts are inevitable on child's mind.

This could be simplified as

If parents try too hard to get involved with schoolwork, it may lead to conflict with the child and affect their relationship

Simplify: Avoid the passive

• Parental assistant in children's education may be faced by some problems.

This could be rewritten more simply as:

• Parents who try to assist their children with schoolwork may face some problems.

Other points

• This essay will outline whether parents are the good tutor or not ==>are good tutors or not.
• It is patently clear that, teachers do not have enough time ==> it is patently clear that teachers do not have enough time

If in doubt, leave commas out!

• On the other hand, parental communication may be disturbed.

On the other hand does not mean in addition or "here's another point" - it means "here's an opposite point" or "in contrast"

Long sentences

First and foremost, it is patently clear that, teachers do not have enough time to spend for each student owing to the number of students in each class, whilst parents can concentrate on their own child on help him to do his exercises (43 words)

All in all, so far I could judge, the above-mentioned reasons might shed light on my subscription to the view that parents regarding to their education can help their children, but their assistant should be organized because of their knowledge and behavior. (42 words!)

Try not to use "above-mentioned" - just use "these." Don't add too many beginning phrases to the sentence: In conclusion, as far as I can see, in my opinion, it is patently clear from the above, I think parents should....  Just say what you want to say.  Keep sentences shorter than 20 words. Your average sentence length should be about 12 words. If you write 20 sentences at 12 words average, that's 240 words - perfect for IELTS!

Here's a simpler version of your conclusion:

All in all, parents can help their children, but they need to keep their assistance within limits. Their expertise is in supporting and encouraging the children, not replacing the teacher.