Perfect means up to the mark. We always say this when the work has been done or completed. In grammar, perfect means that the work was completed in past. The Present perfect, however, means we are talking or thinking about the time when the work was completed but in relation to the present.
The hint to identify whether it is present perfect or not is that we use has/have + third form of verb (ed) past participle
Also, there are certain situation where we should use present perfect tense in our vocabulary:
Situation 1 – When the time of action is not over.
Examples
1. I have eaten my food. (I am full)
2. I have gone to the market today. (the specific time in today is not mentioned)
Situation 2- When using the words for and since
Examples
1. I have worked in this organization for two years now.
2. I have taught in this academy since I was 20 years old.
Situation 3 – When talking about an action that has been repeated between past and present. (action that started in the past and has repeated many times)
Examples
1. I have visited her six times.
2. She has explained the concept in class many times.
Situation 4 – When the time of action is not important. Here more focus is on whether the action has been completed.
Examples
1. Have you submitted the project?
2. Have you read this book?
Situation 5- When talking about an action that was recently completed using word just.
Examples
1. I have just finished my dinner.
2. She has just called Rohan to wish him a happy birthday.
Situation 6- In negative sentences, use not after has/have.
Examples
1. I have not finished my dinner.
2. She has not called Rohan to wish him a happy birthday.
In interrogative sentences
Examples
1. Have you cleaned your room?
2. Yes, I have cleaned my room.
Note- Do not use present perfect tense with words that indicates time like yesterday etc.
Examples
1. I have finished my work yesterday
Instead, I finished my work yesterday.
2. She has visited me last Sunday.
Instead, she visited me last Sunday.
3. Ram has arrived at 8 o’clock.
Instead, Ram arrived at 8 o’ clock.