A good plan today is better than a perfect plan tomorrow.-George S. Patton

Key:

Present Perfect tense: This tense is formed with Present tense of the verb have and the past participle of a verb.

Present Perfect Continuous tense : This tense is formed with has/have been and the -ing form of the verb.

Rule: 

1. In case of 1st Person- (I/We)- have(present perfect tense)/have been(present perfect continuous)
2. In case of 2nd Person- (You)- have(present perfect tense)/have been(present perfect continuous)
3. In case of third person
   1. Singular(He/She/It) – has(present perfect tense)/has been(present perfect continuous)
   2. Plural (They)-have(present perfect tense)/have been(present perfect continuous)
4. The Past participle form of the verb i.e the third form of the verb is used in all types of Present Perfect Tense.

Use: Present perfect is used in the following situation:

1. For something that started in the past and continues in the present- 

1.   She has worked in the bank for nearly 5 years.-Present perfect tense
2. She has been working in the bank for 5 years-Present Perfect Continuous tense.

Note: We normally use the present perfect continuous for these type of tenses.

2.  For something that we have done several times and continues to do in the present-

1.  I have played the Guitar ever since i was a kid.-Present perfect tense.
2.  She has been watching the show ever since it was started.- Present Perfect Continuous tense

3. When the time referred to has not finished-

1. It has rained a lot this month.-Present perfect tense.
2. She has been running since morning.- Present Perfect Continuous tense

4.  Things repeated in between the past and the present-

1. We have seen Titanic six times.-Present Perfect Continuous tense
2. She has visited the doctor frequently.-Present perfect tense.

5. Actions completed with the very recent past– (with the use of just)

1. I have just finished cooking.
2. She has just joined the classes.

6. When some activities remain unknown-

1. Someone has eaten my cookie !
2. She has not come to class for 3 weeks.