Dear friends, just a small remark on the subject. While the forms are interchangeable, using simple past is still considered a feature of American English, and one is more likely to hear the simple perfect counterpart in educated British English.

3) All the class is going to be punished, because someone has written an offensive anonymous essay. You know, I am not even sure that Present Perfect is necessary in this sentence :P. Isn't it optional in AmE and BrE? I used it on purpose,

I might be wrong, but I'm afraid "Who has completed all the exercises" might be ok, and "Who has demolished such a beautiful cemetary" might not. I see that in Jim's and Amy's examples there always seems to be an

However, we usually prefer as simple past tense when we identify the person, thing, or circumstances responsible for a present situation (because we are focusing on the past cause, not the present result). That would explain my aversion to the use

Who has let the cat in? (= look at the mess the cat has done ..) Who let the cat in? ( who was the person responsible ..) I think this explanation seems a little iffy in my opinion. If you walk into your kitchen and saw a

I'm going to quote some stuff that can be found in Swan's Practical English Usage, which is often considered to be the most complete ESL grammar book available. This should apply to BrE, I guess. Here are some short paragraphs written by

If a situation calls for present perfect, regardless whether it's in Britain or in the US, the same grammar rules still applies. I was told there is this difference: American: I just saw your sister / I've just seen your sister. British:

Is there a difference in the meaning of these two phrases? "Yes, I got your message." "Yes, I did get your message." The difference is in emphasis. The second is emphatic. Are both of these phrases in Simple Past Tense? Yes,

"If you knew what I had gone through, you would surely pity me." Don't listen to these people. You can change it to "have" because only the first verb has to be in the subjunctive mood. The verb "knew" is

Hi, I just feel that I hear and use: Maybe. But do you talk a lot to native speakers? I've done this, she's this, he's that, we've been planning, they've got a nice car, she has the same sweater as I... The