A couple of questions about the present perfect.

Hello teachers,
Two questions:
a) I think there is the ‘resultative perfect’ in the sentences below; right? The result in the present could be that ‘his boss was angry with him’, couldn’t it?
b) In sentences 2 and 3, is it necessary to write ‘up to now’ at the end of the explanations to differentiate it with the simple past or not?

  1. Because of the present perfect tense, the sentence informs us of what Peter has done at an indefinite point in time in the past.
    [color=blue]Peter has arrived late at work.
  2. Because of the present perfect tense and the adverb of number, the sentence informs us of the exact number of times that Peter has arrived late at work at indefinite points in time in the past up to now.
    [color=blue]Peter has arrived late at work three times.
  3. Because of the present perfect tense and the adverb of quantity, the sentence informs us of the indefinite quantity of times that Peter has arrived late at work at indefinite points in time in the past up to now.
    [color=blue]Peter has arrived late at work several times.

Thanks in advance.

I believe your 2 and 3 are “repeated actions that happened at an unspecified time before now… Examples: I’ve seen that movie a dozen times. He’s been absent twice. They’ve made a lot of new friends.
When the present perfect tense is used to show repeated actions, so far/in/during/over the past/last _____ are very common; so are some frequency adverbs.
Examples: I’ve seen that movie a dozen times so far. I’ve seen that movie a dozen times in the past two years. I’ve frequently seen that movie. /I’ve seen that movie frequently. He’s been absent twice during the past week. He’s often been absent. /He’s been absent often. She’s made a lot of new friends over the past few days. eslcafe.com/grammar/present_ … nse04.html

–As to your 1), I see it just putting emphasis on the result. What were the reasons behind it and how you expect things will unfold, isn’t stated—the result is what matters.
For example: He had a fight with burglars in his house/his car wouldn’t start/he couldn’t say ‘good bye’ to his young wife…–has arrived late…
His boss got furious and said he would be fired/the meeting he was expected to chair had ended/…–anything could happen.
But what we focus on: Peter has arrived late…

Hello Eugene,
Thank you very much for your explanations and examples. Though I don’t agree very much about the use of the present perfect with unfinished actions as the web page says. I prefer to use the present perfect continuous to indicate the duration of an action from past to present.
I’ve read that only with these verbs ‘live, work, teach, and study’, to indicate the duration of an action from past to present we can use either the present perfect or the present perfect progressive with essentially the same meaning.

RtL

I believe we were dealing with the present perfect…
As to the ‘agree\disagree’ issue, personally, I strongly disagree with the English using Latin rather than ‎Cyrillic alphabet.