Confucius is a great educator and thinker whose idea still influences us.
问题描述：
Confucius is a great educator and thinker whose idea still influences us.
为什么用influences?而不是influence?
答
influences是定语从句whose idea still influences us.的谓语,主语是idea,单数,所以谓语influences也只能用单数.
辨清句子的主语是解答此类问题的关键.
祝你进步,更上一层楼