Present Perfect Tense

Definition 

This tense deals those activities or actions that occurs in present time right now and finished before a short while and the outcome is front of us. The present perfect tense expresses the idea that something happened in before now, at an unspecified time in the past.  Since is used for a particular time and  for is used for a duration of time also utilize in this tense. For example a person is about to perform an action. He has planned to do act in present time. He is performing an action. Continuously he is doing his act. He has performed an action and the action is completed in recent past and the result is front of us.

Usage of tense

1. In this tense we use third form of verb. 

2. In this tense we use has and have as aiding action word.

3. Has used for singular subjects she, he, it and one name.

4. Have  is utilized for plural subjects you, they, we and two names but for I subject we use have too.

Positive formula with Instances

Subject + aiding action words+ third form of verb + Object

1. We have won the match.

2. She has learnt her lesson.

3. He has cut the cake.

4. They have heard the news.

5. I have been here since one clock.

Negative formula with Instances

Subject + Aiding action words+ not +third form of verb + Object

1. We have not won the match. 

2. She has not learnt her lesson.

3. He has not cut the cake.

4. They have not heard the news.

5. I have not been here since one clock.

Interrogative Formula with Instances

Aiding action words + Subject + third form of verb + Object

1. Have we won the match?

2. Has she learnt her lesson?

3. Has he cut the cake?

4. Have they heard the news?

5. Have I been here since one clock?