I've never been above toilet humor.
Good gods of English, why on earth or in this heavenly solar system does the universal language, any language for that matter, need such a fine-toothed comb to express events bygone and soon-to-be forgotten? At some time, between the capitalized first letter and the pointed period of fluency, English students must tackle the horrible past simple vs. present perfect fiasco, and in turn, the EFL teacher is forced to distill the mysteries of two closely related verb tenses that might not have been were the world a gentler, more understanding place.
For the layperson, simple past verbs are those which regularly end in –ed (of course, this species is rampant with exceptions, the was/were-s, did-s, broke-s, forgot-s and so on), and in the grammarians world, these feral creatures are designated for expressing past events that have been completed with said events having happened at a particular, known time. In other words, “I taught you the glories of simple past yesterday!” or, more negatively, “Some years ago, I didn’t care a jot about simple past or present perfect, which brings us to my next point...”
Continuing, the present perfect are those utterances beginning with have or has plus what the writers of EFL books have generously denoted as “the third form”, “verb three”, “participle form”, and/or “the past participle”, allowing for the utmost in clarity. So, was/were changes from was/were to have/has been, did to have/has done, broke to have/has broken, and…To the point, present perfect is used when events have occurred but without mentioning a particular time, when the event began in the past but has continued right up to the present, or if the event has just happened with visible results, such as “I’ve just alienated readers by getting far too grammatical.”
I hate when this happens, especially as folks from the US suffer as the butt of many linguistic gags, but Americans have the well-deserved reputation for completely disregarding the specified time vs. unspecified time section of the rule. We (I’m certainly one of these troublesome disregarders) tend to ask “Did you read this?” as opposed to the more correct “Have you read this?”. We exclaim “What the f- did you do!” instead of “What the f- have you done!” Okay, okay. I know, I know. I made my point. (Attention US citizens: That was a test: If you didn’t recognize* the grammar faux pas I’ve just committed, perhaps you should reread this paragraph.)
The Brits, on the other hand, fulfill their linguistic obligations, effectively and expertly using present perfect like little fairies of perfect diction. As a result, I often turn to Emma, my Queen’s English wife, for precariously impertinent cases of past simple vs. present perfect. However, the minute and unimportant (from a communicative standpoint) details sometime still leave us, seven-year veterans of teaching English grammar, lifelong speakers of English, in a tizzy, such as whether or not we use * “If you didn’t recognize the grammar faux pas I’ve just committed” or “If you haven’t recognized the grammar faux pas I’ve just committed”. I’m still not sure which is correct, and more unfortunately, I believe both are with slightly different meanings.
The reason such tizzies occur, in my humble yet piqued opinion, is that differentiating between past events with specified times and past events with unspecified times, as you too may have also concluded by now, is probably more aggravating than useful. “I took a poo.” “When?” “Five minutes ago.” seems to work just as well as “I have taken a poo.” “When?” “Oh, let me specify: I took a poo five minutes ago.” Such a proclamation might seem grammar lazy, ultra-Americano, but damn it, if all we want is to be understood, and if our wife knows not to go in the bathroom just yet, then can’t we just live in harmony.
Okay, I’ve said my piece, or I said it, whichever you prefer.