Present Perfect Simple

Present perfect simple　


　The present perfect has perfect aspect, which means that it is used to refer to a subject's past actionsor states while keeping the subject in a present state of reference or in a present state of mind. Therefore, in English, the following logic helps to understand the tense: Think of the words in the construction separately: "have" (or "has") is in the present, and the past participle is in the past. For example

"I have gone to the cinema" implies that the subject has completed a certain action (this is what "gone to the cinema" relates), but that the subject is, in a sense, "holding" or "possessing" that completed action in the present time (this is what "I have" relates to).

　 In other words, the subject is in a current state (now), and a past action that the subject has done or a past state that the subject has been in, is being referred to from the current state of the subject, which is the present time.

This differs from the simple past tense,

For example

"I went to the cinema", which implies only that an action happened, with the subject having norelationship at all to the present.Another example

・The boy saw the car.
(Emphasis is on the fact that the boy saw the car.)

・The boy has seen the car.
(Emphasis is on the present state of the boy, resulting from the fact that he saw the car.)

・I left Brazil eight years ago.

・I have left Brazil for now.



　In summary, both the present perfect tense and simple past tense are used for past actions or states, but the present perfect describes the present state of the subject as a result of a past action or state
(i.e., the subject is being talked about in the present),

whereas the simple past describes solely a past action or state of the subject (i.e., the subject is being talked about in the past). 

The present perfect simple is often used with

・since
・for
・since
・over the last few years(months)
・before
・yet
・just
・already

ADVERB PLACEMENT

・always
・only
・never
・ever
・still
・just…

　Example　

・You have only been waiting here for one hour.
・Have you only been waiting here for one hour?

1.Form

2. Use 


　 Unspecified Time Before Now 　

　We use the Present Perfect to say that an action happened at an unspecified time before now.

　 The exact time is not important.

You can not use the Present Perfect with specific time expressions such as: yesterday, one year ago,last week, when I was a child, when I lived in Japan, at that moment, that day, one day, etc.

We can use the Present Perfect with unspecific expressions such as: ever, never, once, many times,several times, before, so far, already, yet, etc. 

　Duration From the Past Until Now (Stative Verbs)　

With Stative Verbs , we use the Present Perfect to show that something started in the past and has continued up until now. "For five minutes," "for two weeks," and "since Tuesday" are all durations which can be used with the Present Perfect.