OK, let's look at this:
Firstly, there exists in Vietnam a stark reality that more and more pupils and students spent days and nights playing online games at the expense of theirs studies.
There are two actual mistakes-
spent and
theirs. It should be present tense, because they still do it, and we should use the possessive adjective
their before a noun-
theirs is a pronoun and replaces the noun. So, the sentence is actually fairly good grammatically. however, it doesn't read very naturally to me, so let's see how we can change it. I like the phrase 'stark reality', so we'll keep it, but I don't like 'there exists' much. I would say something like this:
The stark reality in Vietnam is that more and more....
Much of your writing is good, but there are parts where the meaning is obscure, so it is more a matter of working on phrasing than anything to me.
Here's an example:
They heap much raise on little goodsides of online games while concealing its several drawbacks.
OK, 'raise' should be 'praise' and 'goodsides' in not one word, and formally, we shouldn't use 'little' with a plural.
They heap praise on the few good points of online games, while concealing their many drawbacks.
That sounds clearer to me.
What you should do in my opinion, is:
a) Watch out for tenses- you seem to use the past on a few occasions where the present simple or present perfect would be better. If it is in present time, use the present and if it began in the past but is still imortant or hasn't finshed, use the present perfect (progressive)
b) Check prepositions (boast of/about)
c) Be`acreful with vocab- you use 'whereas' incorrectly- it's not the same as 'where'
d) I would suggest being careful about the vocabulary. It seems at times that you are trying a bit too hard and overloading sentences with flashy words to catch the eye. I would recommend being a bit more judicious with this.
Organisation and structure are good. My general advice it try to keep the vocab a bit simpler and avoid the temptation to hit me with so many words.
