It was dark.I couldn't see the thief.But I could hear him sp

題目：

It was dark.I couldn't see the thief.But I could hear him speak / speaking.選哪個?
答案給的是speak。請給我原因

解答：

It was dark.I couldn't see the thief.But I could hear him speaking.
hear sb.do 聽見某人在做（過程）
hear sb.doing 聽見某人在做（動作）