误She switched on light.
正She switched on a light.
析light作“灯,灯光”解时常用作可数名词。
暴露在光线下的植物长得快。误Plants grow rapidly when exposed to lights.
正Plants grow rapidly when exposed to light.
析light作“光线,亮光”解时多用作不可数名词。
误In the middle of the room stood a table with a lit lamp on it.
正In the middle of the room stood a table with a lighted lamp on it.
析light的过去分词有lighted和lit两种,单独作前置定语时应该用lighted,其他情况多用lit。