The Present Perfect Tense connects the past to the present. It describes an action that happened in the past and goes right to the present moment. The time of occurrence of the action is not mentioned. Usually, the time is not important or is not necessary to know. It is the result of the action that matters which may also come after the present moment.
To express something in the present perfect tense, it must use the simple present tense of the auxiliary verb have or has depending on whether the subject or noun being referred to is plural or singular. The auxiliary verb is followed by the past participle of the main verb (for example, regular verb: have called; irregular verb: has given).
have/has + past participle
|Question form:||have/has||+||subject||+||past participle|
As stated, the time of an action is not mentioned when the present perfect tense is used.
The Present Perfect tense is used:
for an action or situation that began in the past and continues to the present.
to show a completed action.
to express repetition of an action at unspecified time in the past.
The adverbs ever and never are used to show or ask if an action has happened at any time or not at all up to now. They are used mainly in negative statements, and their positions are just before the past participle verb. Ever is often used in questions.
The present perfect tense is often used with other adverbs and time expressions such as the following:
with phrases beginning with "This is the first/second/third ....time"
to answer questions that are asked in the present perfect tense.
We use for + a period of time as an indication of how long an activity has lasted up to the present moment.
The adverb since is used to show a duration from a particular time in the past when the activity began until now.
Just is used to show something has happened only a short time ago. Just is usually placed after have or has and before the main verb in a sentence.
Already is used to show something has been done by or before now or a particular time. It is usually positioned in the middle after have or has and before the main verb or at the end of a sentence. It can also appear in questions. When already is used, the sentence makes no mention of when an action took place in the past.
The word yet is used with the present perfect tense to form a negative sentence or a question. It is used to show or ask about something that is not done until now or until a particular time. The adverb yet is usually used at the end of negative sentences or questions. Sometimes, yet appears in the middle of a sentence.
Difference of meaning between have/has gone and have/has been.
The present perfect tense and the simple present tense
We use the present perfect tense, not the simple present tense, to show an activity that began in the past and has continued up to the present. The words used with the present perfect tense are commonly just, for, and since as shown here.
The present perfect tense and the simple past tense
The difference between these two tenses – present perfect tense and the simple past tense – is that the time of an action is not mentioned in the present perfect tense, but it is usually mentioned in the simple past tense.
We use the present perfect tense when the period of time is not over and the simple past tense when it is over.
For can be used with both present perfect and simple past tenses.
We use the present perfect tense in the main clause (independent clause) and past simple tense in the subordinate clause (dependent clause) of a sentence as follow:
|Main Clause||Subordinate clause|
|We have become friends||since we became classmates.|
The passive form
The passive form of the present perfect tense is used when the action is not done by the subject but rather to the subject. Often, it is not known who has done the action.