Hi, please explain usage of Perfect tense in the following sentence:
"He has pretty much known from the beginning the thing the United States there are certain cities that the famous for certain genres".
Why "has known" but not "He knew from the beginning"?

The phrase "He has pretty much known from the beginning" uses the Present Perfect tense ("has known"), which suggests that the knowledge was gained in the past and continues to be relevant in the present.

Why "has known" (Present Perfect) instead of "knew" (Past Simple)?

  1. Ongoing relevance: The Present Perfect tense is often used when a past action or state still affects the present. In this case, "he has known" suggests that he learned this information in the past and still knows it now.

  2. Unspecified time in the past: The Present Perfect is used when the exact time of the past action is not specified or not important—we only care that it happened and continues to be true.

  3. "From the beginning" as a time marker: The phrase "from the beginning" implies that the state of knowing began at a certain point in the past and has continued up to now. This aligns well with the Present Perfect, which is often used with expressions like "since", "for", or similar structures that emphasize continuity.

Could we say "He knew from the beginning"?

Yes, but the meaning would slightly change:

  • "He knew from the beginning" (Past Simple) suggests that the knowledge existed at that time in the past, but it does not necessarily imply that he still knows it now.

  • This would be more natural if the knowledge was relevant only in the past or if there was a possibility that he no longer knows it.

Example for comparison:

  1. "I have known her for years." (I still know her now.)

  2. "I knew her years ago." (I knew her in the past, but maybe I don’t anymore.)

So, "He has known from the beginning" emphasizes continuous knowledge from the past to the present, while "He knew from the beginning" sounds more like a completed past event without necessarily implying that the knowledge remains.

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Hi, мне поручили небольшое задание и я его уже выполнил как я должен написать письме: I updated the document or I have updated the document?
ChatGPT

It depends on the context and what you want to emphasize. Let me explain the difference:

  1. "I updated the document"
    • This is in the past simple tense.
    • Use it if the action is clearly finished and linked to a specific time in the past (even if that time is implied, not stated).
    • Example: "I updated the document yesterday."
  2. "I have updated the document"
    • This is in the present perfect tense.
    • Use it if the action has a connection to the present moment or its result is still relevant now.
    • Example: "I have updated the document, and it is ready for review."

Which should you use?

  • If you just finished updating the document and want to emphasize that it’s now ready, "I have updated the document" is better.
  • If you’re simply informing about an action you completed at a specific time (or if the timing isn’t relevant), "I updated the document" is fine.

In your case, since you're probably letting someone know about the document being ready now, I suggest:
"I have updated the document."

Past Simple vs Present Perfect