If we had not been born in the same generation, I couldn't have talked with him.
If we had not been born in the same generation, I would not have had any opportunity to talk with him.
If we had not been born in the same generation, I couldn't have had any opportunity to talk with him.
"生まれた時代が違ったら彼と話をすることはなかっただろう"
仮定法を使います。
生まれた時代が違ったら （同じ時代に生まれていなかったなら）
If we had not been born in the same generation, I couldn't have talked with him.
If we had not been born in the same generation, I would not have had any opportunity to talk with him.
If we had not been born in the same generation, I couldn't have had any opportunity to talk with him.
日本 
