Present Perfect

We use "present perfect" in the following cases:

1. To describe a situation that started in the past and continues in the present.

Ex: "I have studied for two hours"

2. To describe experiences.

Ex: "I have seen elephants in the zoo"

*We can use "ever" to highlight a positive experience, for example:

"My last pijama party was the best day I have ever had!"

3. To describe something that we have done several times in the past and continue in the present.

Ex: He has written two poems and he is working on a new one!

*We can use "ever since" to describe a starting point, but also the starting point of a experience.

"I have played the guitar ever since I was a child".

We use present perfect with times adverbial: "just" (to describe an action that happened recently) "already" (to describe an action that happened before you expected) and "yet" (to describe an action that you expect, but has not happened yet).

Ex: "He has just watched "nemo"".

We use "ever" to make questions related to experiences and "never" to highlight negative aspects of a experience.

Ex: "Have you ever touched a monkey before?"

Been ≠ Gone: "been" refers to someone who has visited a place and came back, but "gone" means that someone has visited a place but he has not returned yet.