1. more than 的主要用法①(指数量)多于。如：I’ve known him for more than twenty years. 我已认识他20多年了。20② 不只是，不仅仅是(通常后接名词、动词、从句等)。如：He is more than a father to her. 他待她胜过父亲。He more than smiled, but laughed. 他不只是微笑，而是放声大笑。The result was much more than I imagined. 结果远远超过我的想像。③ 极其，非常(通常后接形容词、副词或分词等)。如：She was more than kind to us. 她对我们很友好。He was more than upset by the accident. 这个意外事故使他非常心烦意乱。④ 难以，完全不能(其后通常连用情态动词 can)。如：
That is more than I can tell (=I can’t tell that). 那事我实在不明白。

2. less than 的主要用法①()不到，不足。如：It’s less than a mile to the station. 去车站不到一英里。In less than an hour he finished the work. 没要上一个小时他就做完了工作。② 比…(小)少。如：Two is less than Three. 二比三小。She eats less than she should. 她吃得比她应该吃的少。③ 一点也不。如：He was less than helpful when we arrived. 我们到达时他一点也不帮忙。