eat 和have 都可以表示“吃”,但是have意思更加广泛,可以表示“有,从事,允许,喝”等含义.
1.eat作“吃”解时,一般是指吃固体食物.
We eat rice every day.我们每天吃米饭.
They eat a lot of / often eat potatoes.
She likes eating dumplings.
eat也可用“喝”解,后多接soup（汤）.强调动作,多用于美国英语中.
2.have作“吃”解时,主要用于一日三餐（breakfast,lunch,supper）之前,或与meal连用.
We often have lunch at school.
have用在口语中表示请求或邀请的句子里,也可表示“喝”.
Would you like to have a glass of milk?你想喝杯牛奶吗?
Let’s have a drink of tea.咱们去喝点茶吧.
eat后面可以接具体的食物（固态）,也可以接泛指的,如,eat eggs,eat dinner
have后面lunch,dinner之接类的泛指（比eat常用）,以及液体的食物,如 have a cup of tea
have作“吃”解时多用于“吃饭”,如have breakfast(吃早饭),have lunch(吃午饭),have supper(吃晚饭),have dinner(吃正餐),have a meal(吃一顿饭)。eat作“吃”解,多用于吃水果、鱼、肉等,~1]eat an apple(吃苹果),eat a banana（吃香蕉）
have多用于吃早饭，午饭，晚饭。而eat多用于吃什么东西。
have 是用餐和吃饭，强调整个吃饭的笼统过程，多用于短语中。
eat 很多时候，强调吃这个动作，就是强调把东西放进嘴，这个动作，略微表 示进行时的倾向。
have breakfast/lunch/dinner/breaklunch She is eating a late lunch.
