(1)作形容词用法，

a little+不可数名词

Mrs. Caan needs a little help getting her groceries home. 

凯恩夫人需要一点儿帮助才能把杂货弄回家。

A little food would do us all some good. 
吃一点儿东西会对我们大家都有些好处。

a little+可数名词

I have a little boy of 8.我有一个8岁的小男孩。

James usually drives a little hatchback. 

詹姆斯通常开一辆小巧的掀背车。

(2)a little副词用法，修饰动词或者比较级

He walked a little by himself in the garden. 

他在花园里独自散了会儿步。

If you have to drive when you are tired, go a little more slowly than you would normally.

如果不得不疲劳驾驶，那就开得比平时慢一点。

(3)a little代词用法

They get paid for it. Not much. Just a little. 
他们拿到工资了。不太多，就一点点。

备注：little用法同上，a lot只能当做副词使用。

Do you sweat a lot or flush a lot?  

你常出汗或是脸上常发烫吗？

I learned a lot from him about how to run a band.  

我从他那里学到了许多关于经营乐队方面的东西.

He was a very mechanical person, who knew a lot about sound.  

他精通机械，了解许多有关声音的知识。

Matthew's out quite a lot doing his research. 

马修经常外出做研究。

I like you a lot(very much) 

我很喜欢你。

They went out a lot, to the Cafe Royal or the The Ivy. 

他们常常出去玩，一般是到皇家咖啡馆或者常春藤那里。

He talks a lot about his own children.  

他经常谈到自己的孩子。