18/08/26 02:42:41.58 e8N0/0Ka0.net
それと
canとbe able toの区別もついでに書くと
だいたい、どちらも一般的な能力について表すもの
で、そういう時はどちらも使えます。
つまり、 Things that we can or we could do <<at any time>> in the present or in the past.
She could read when she was three.
She was able to read when she was three.
というわけですが、
<<we managed to do on specific occasions in the past>>
の場合にはcouldは使えず
was/were able to
を使います。だけど否定形(could not, were not able to)
の場合はcould notも使えます
と書いてた
URLﾘﾝｸ(www.englishgrammar.org)