Present Perfect Tense

(+) S + Have/Has + V3 + O         => We have eaten breakfast
(-) S + Have/Has + Not + V3 + O => We have not eaten breakfast
(?) Have/Has + S +  V3 + O? => Have we eaten breakfast? Yes/No

CONVERSATION ...
Steve   : Hey, this sounds strange – snails with garlic. Have you ever eaten snails?
Kathy  :Yes, I have. I had them here just last week.
Steve   : Did you like them?
Kathy  : Yes, I did. They were delicious! Why don’t you try some?
Steve   : No, I don’t think so.
Waiter : Have you decided on an appetizer yet?
Kathy  : Yes, I’ll have a small order of the snails, please.
Waiter : And you, sir?
Steve   : I think I’ll have the fried brains.
Kathy  : Fried brains? I’ve never heard of that! It sounds scary

EXERCISE ...
1.  A : Have you ever ……. (be) to a picnic at the beach?
     B : Yes, I ……. . We …… (cook) hamburgers.

2.  A : Have you …. (try) sushi?
     B : No. I ….., but I’d like to.

3.  A : Have you ever ….. (eat) Mexican food?
     B : Yes, I ….. . In fact, I ….. (eat) some just last week.