Present Perfect Tense
English Present Perfect Tense is formed with a present tense form of “to have” plus the past participle of the verb (which can be either regular or irregular in form). This english tense indicates either that an action was completed (finished or “perfected”) at some point in the past or that the action extends to the present. In other words, The Present Perfect is used to express actions that happened at an indefinite time or that began in the past and continue in the present. This English Tense is also used when an activity has an effect on the present moment.
Present Perfect Tense Form: Positive Form: S + have/has + Verb3 Negative Form: S + have/has Not + Verb3 Interrogative: Have/has + S + Verb3
Verb3, I mean past particile form of the Verb. I can be regular Verb or irregular form of the Verb. I am sure you are familiar with these:
Irregulare Verb: Go – Went – Gone (Verb3)
Regular Verb: Study – Studied – Studied (Verb3)
Irregular Verb again: Make – Made – Made (Verb3)
Later, at next pages of English Tense Lesson I will mostly write Verb3, and I mean that is Past Participle form of the Verb, okay? 
Example of Present Perfect Tense of English:
-I have written a letter
-You have taken my pen
-He has drunk milk
-They have eaten fried rice
Usually the words like the following is used with Present Perfect Tense: just, ever, never, already, recently, yet, etc.
For example:
-I have just broken the glass
-He has just closed the door
-Have you ever seen the ghost?
The Negative form of Present Perfect Tense is also very easy. You just need to place “NOT” after the has or have. Yes, the same way as you do for Present Continuous Tense. Question form of Present Perfect Tense is made by starting the sentence with Has or Have.
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