I teach English. My first language is Portuguese. Saying that the present perfect refers to an action which happened some time in the past and has an effect in the present, can be very confusing and lead to misunderstanding when teaching English to Portuguese speakers. It has to do with our grammar. So, I agree with all the other teachers who find it difficult to explain and to understand.

I think the 'balance' explanation you posit for determining whether one uses 'in' or 'on' is a bit specious. It happens to be true in a lot (but NB not all!) cases and it might be useful to help learners to remember when to use which preposition, but it isn't 'the reason' we use those words. There are several overlapping considerations, the most important of which is analogy to other forms. -First: less derived forms of transport: one goes 'on' foot, one rides 'on' a horse. These are obvious: one needs to be on top of the ground to walk on it, on top of a horse to ride it, et cetera. -Second, more derived forms of transport (i.e., vehicles). It's not as simple as requiring balance or not. I put it to you that riding 'in' a horse-drawn carriage would be just as (if not far more) rickety and shaky and therefore taxing to one's balance than riding 'on' early buses or trains. For said horse-drawn carriages, the prepositions are clear: if you're inside the coach, you use 'in,' if you're the one driving the coach or sitting outside on a running board, you use 'on.' So far so clear. This is why we use 'in' for cars, then: by analogy, they are the most similar to riding inside carriages. The first cars were essentially horse-drawn buggies without horses, after all. It gets complicated when referring to horse-pulled open-topped carts or just 'conveyances' writ large. Despite the lack of a roof (AND despite the fact that using carts as a method of travel would certainly also require balance) it feels more natural in my dialect of English to say "I was riding 'in' the cart" vs. "I was riding 'on' the cart." Both work, of course, but using 'in' feels just that much better to my ear. One definitely travels 'in' a wagon, though. That's undeniable. For ships/boats, the distinction is whether the craft has a deck (i.e., somewhere to stand 'on,' no matter if there are seats anywhere else): you travel 'in' a rowboat/canoe, but 'on' a sailboat, steamship, motorboat, et cetera. If the sailboat or motorboat were small and lacked a deck, I would say 'in.' Submarines are interesting. I've known sailors to say "I've served 'on' submarines" and "when you're riding 'in' a submarine..." It seems to depend on whether or not you're referring to the submarine in its capacity as a boat with decks (use 'on') or as a mere physical location (use 'in'). Airplanes are an extension of ships. You use 'in' for small planes (i.e., the planes closest in analogy to smaller, deckless boats): "I went up 'in' my Cessna last week," and 'on' for bigger planes with multiple decks, "'I flew in 'on' a 737." Sci-fi even confirms this for space travel: you fly 'in' a shuttlecraft and 'on' the Enterprise in Star Trek; in star wars, you fly 'in' X-wings and 'on' star destroyers, et cetera. Finally, we get to the truly hot take: I think English speakers subconsciously classify buses and trains in the 'big boats' category, rather than the 'carriage/car' category, and therefore we use 'on' for both of them. It tracks: trains are essentially land-ships, and buses are just streetcars/trams that don't run on a fixed track. For purposes of language, a bus' superficial resemblance to other motor vehicles is immaterial. It's a train, and a train is a ship.

I have a Masters degree in teaching English as a second language, and honestly, I’ve noticed that British people tend to use present perfect in many situations in which American English speakers might use simple past. Even when the grammar rules are the same, the way we implement the rules are influenced by our dialect of English, and I find that so interesting.

I beg to differ rsrs actually It is an action in the present the important here is the concept of present You could say for instance that this month is present; so if sonething has happened or not this month, It has happened (or not) in the present. If you say It has happened in your life (present again), so use the present perfect. In a nutshell, If It is contextualized in the present, use the present perfect. The Key point here is the concept of present.

Thank you!! This is the best explanation of the present simple I have ever heard!! As a semi retired English teacher, this one has frustrated me for many years. Teachers simply do not know how to teach this verb, which leaves learners totally confused. The most common erroneous explanation is that it is 'an action which started in the past and still continues in the present'. My advice to all English teachers: watch this video and please don't parrot what you read/hear on the internet.

talking about the results which are true now - present perfect, talking about the results which are true now but still in progress present perfect continuous: i have lived in London for three years but now i'm gonna move to Canada. i have been living in London for 3 years and i like it. am i right? i'm not a native speaker.🙁

So present perfect: "I ate an egg, I have to puke now." ? Past perfect would be: "I ate an egg, and I puked." ? Future perfect would be: "I just ate an egg, I might have to puke soon." ? Oh, final question; what's simple perfect?

What about the submarine? Though we can walk and stand in it, we say in not on submarine, maybe it's not a public transport, is it?

So what's the consequence in the sentence 'I've lived here for three years'? 🤔