＊This grammar can be used to describe time, distance, or extent/scope.
FORMATION: Ｎ + にわって・にわたり Ｎ1 + にわたる + Ｎ2
Shidareさん。 The reason why it is にわたる is because it defines what the noun is. 2年にわたる新しい道路の建設工事がやっと終わった This can be separated like this: 建設工事 = Construction work 道路の建設工事 = Construction work of the highway 新しい道路の建設工事 = Construction work of the new highway 2年にわたる新しい道路の建設工事 = Construction work of the new highway that spanned 2 years So the real noun here is 道路の建設工事, but 「2年にわたる新しい」defines some properties to the noun as well. This grammar is very common when you describe something about a noun. Other examples may be: 「これはネズミを食べる猫です」 This is a cat that eats mice. You need to have the verb in it's dictionary form to define something about the noun that comes after ^^
Here for the same reason as Shidare. Anyone? newjlpt.com gives this: 名詞 + にわたって ・ にわたり 名詞 + にわたる + 名詞 But it doesn't seem consistent.
Can anyone explain the difference betweeen にわたる and にわたって？ Specifically, I am looking at a question that says ２年（ ）新しい道路の建設工事がやっと終わった。 I do not understand why にわたる is correct にわたって and is not, according to the answer key.
#5696 Changed from あの子は英語ドイツ語中国語フランスから日本語にわたって to あの子は英語、ドイツ語、中国語、フランス語、日本語にわたって I am not sure if "knows many languages" means いろんな言葉をよくできます。Maybe いろいろな言葉を知っています。would be better.
Thanks for the comment seanohaganさん. I fixed the Japanese version according to it.
 should say hours not years in the English translation.
ludi, にわたって means "over" or "for" as in, "for over 10 years." にかけて means "to" as in, "from January to April."
What's the difference with にかけて ?
If you are thinking of "わたって" as having the meaning of "cross-over," then わたって would have to be rendered as 渡って which would mean "cross over" as you do over the bridge.
I am thinking that にかわって means " in place of" ...please look at this sentence. 父にかわって、私が結婚式に出席しまた。This also follows the form of にかわり instead of.
Very similar to o tsuujite (2) and o tooshite, but only used for things that have finished. O tsuujite (2) and o tooshite are used for ongoing things. Always follows a noun.
i think it has "crosses over" meaning too, as this phrase is sometimes used when revenue crosses over a breakeven point.
More like "over the period, throughout the span, across the range"
I am not sure if わたって has the meaning of "cross over." I think you use "越える" You would say 収益が損益分岐点を越えた when revenue crosses over a breakeven point.