1. Present Perfect and Past (현재 완료와 과거) ¶

1.1. Unit7. Present Perfect(1) (I have done) ¶

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 A. Tom is looking for his key. He can't find it. He has lost his key.(= He lost it and he still doesn't hav it.)
    The present perfect : have/has + past participle (have/has + 과거분사)

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 B. When we use the peresent perfect, there is a connection with now. The action in the past has a result now.
    (현재 완료를 언제 사용하느냐? 현재와 뭔가 연관 관계가 있을때.. 즉 과거에 있었던 일이 현재에 영향을 미칠때. 역시 어렵군..;;)
    ex) He told me his name, but I've forgotten it.(I can't remember it now.)

    We often use the present perfect to give new information or to announce a recent happening.(새로운 정보나, 최근의 사건을 보도할때도 쓰인답니다.)
    ex1) The road is closed. There's been an accident.
    ex2) (from the news) The police have arrested two men in connection with the robbery.

    We also use the simple past some situations.( ... 어쩌라는 거야..ㅠ.ㅠ 쓸거면 확실하게 한군데만 쓰던지..;;)

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 C. We ofte use the present perfect with just, already, and yet. You can also use the simple past.
    (대개 just,already,yet과 같이 현재완료를 쓰지만, 단순과거에도 쓸수 있단다. 제기랄--;)
    Just = a short time ago.
    ex) I've just had lunch. or I just had lunch.
 
    We use already to say that something happened sooner than expected.(예상했던것보다 더 빨리 사건이 터졌을때 쓴다)
    ex) I've already mailed it. or I already mailed it.

    Yet = until now. It shows that the speaker is expecting something to happen. Use yet only in questions and negative sentences.
    ex1) Has it stopped raining yet? (simple past도 가능!)
    ex2) I wrote the letter, but I haven't mailed it yet. (역시 simple past 가능)

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 D. Don't use the present perfect when you talk about a finished time.(이미 끝난일 가지고 현재 완료 쓰지말란다. 당연한 얘기)
    ex) It snowed last night.(not has snowed)

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1.2. Unit8. Present Perfect(2) (I have done) ¶

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 A. When we talk about a period of time that continues from the past until now, we use the present perfect.(앞에 나온말)
    ex) Have you ever eaten caviar?

    been (to) : visited
    ex) I've never been to China. Have you been there?

    Here are more examples of speakers talking about a period that continues until now(recently/ in the last few days/ so far/ since breakfast, etc.)
    (현재 완료에는 저 구문들을 자주 쓴다네요.)
    ex) Everything is going well. We haven't had any problems so far.

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 B. We use the present perfect with today/ this morning/ this evening, etc. when these periods are not finished at the time of speaking.(그렇대요;;)
    ex) Have you had a vacation this year?

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 C. We say, "It's the first time something has happened."(present perfect) (이건 뭐하자는 건지..;;)
    ex) Sarah has lost her passport again. It's the second time this has happened.(not happens)

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