The verb “have” is transitive. That means we must always say what we ate or will eat. For instance, in the restaurant exchange, the man said they would have the oatmeal. “Eat” is intransitive, which means we do not have to say it. So, you can say this: I’m really hungry. Let’s eat!

You can use have instead of other words for certain actions we do regularly. Have a party, have a meal, have a go at sth (to try). I ate spaghetti is ok, but if you want to be more native, use I had soaghetti...

Eat means to put food through your mouth, chew and digest it. Have means to hold or maintain something as your own. You more than welcome to book a trial lesson with me. Please do check out my profile..

You can have both food and drink, but only eat food. I will have some beer with a friend after work. or Can she have some tomatoes in that salad? I can't eat milk or drink meat. But I can have both.