lang8で英語を添削してもらう

2013年の日記

ｌａｎｇ８の効果

(添削前）
ａｂｈｉ
The only one good thing that Japan got by The world war 2 is the peace constitution.

（添削後）
The only good thing that Japan got from World War 2 is the Peace Constitution.

1) you don't need to put "one" if you have "only" in the phrase
2)  could sometimes mean "by" but from the context of your sentence, the preposition should be "from." 
3) World War 2 and Peace Constitution are proper nouns, so they need to be capitalized

Thank you for your correction!

（質問）
abhi 
Why I don't need "the" for World War 2? Why I need "the" for Peace Constitution?

（答）
The number "2" after World War identifies which World War you are talking about so "the" is not necessary. But if you had used "the Second World War" where "second" is before World War then "the" is necessary. In the Peace Constitution, "Peace" which identifies "Constitution" comes before it so we need to use "the".

So the pattern is, if you have a noun/adjective that identifies a noun before the noun, use "the." ex. the third chapter (third identifies which chapter)
If you have it after a noun, omit/do not use "the." ex. chapter three (three identifies which chapter)

Of course there might be exceptions to this.

うーん。とても勉強になる。
おそらくこのようなことは長く英語圏で暮らすか、分厚い文法書を最初から最後まで読み通せば（そして何回も読み返せば）マスターできることだろうが、ｌａｎｇ８では、自分の必要性に応じて効率的に学習できる。

しかも無料だ。

僕は同じようなことを日本語文に対して、してあげている。