新概念英语第一册82课有几个句子的用法弄不清楚,

新概念英语第一册82课有几个句子的用法弄不清楚,
1、I had a cup of coffee.与 I drank a cup of coffee.
2、They had a meal at a restaurant.与 They ate a meal at a restaurant.
3、We had a holiday last month.与 We went for a holiday last month.
4、You had a good time.与 You emjoyed yourself.
5、They are having their lunch.与 They areeating their lunch.
6、I had a glass of milk.与 I drank a glass of milk.
以上每个句子中的两句话有什么用法上的区别?或者语法上面的区别?