As I said, this issue is essentially a matter of getting used to the language. Pay attention to what’s different (you’re doing a great job of that) and keep an open mind about it, expect to be surprised and even freaked out time and again. It’s part of the fun.
However, let me expand about some of the difficulties you’ve mentioned because I think this topic makes for interesting conversation and hopefully it can help you get used to the differences between languages. My excuses if it’s too long/boring. Feel free to skip it. The most important part is highlighted at the end (“FINAL NOTE”).
Let me focus on one of your examples “en la pared” = “on the wall”
En/on are prepositions (one category of the pesky connectives that make trouble for you and other learners).
As a native speaker you have a clear mental image of when “in” and “on” are to be used. So much so that you think you know what they “mean”. However, I’d argue that this is mostly an illusion. Prepositions don’t have meaning, at least the same way that nouns such as “table” or “chaiir” have.
Examples: you live in a country, but work on a farm, you commute in a car but on a bus, in case, but on condition, …
You may argue that these are edge cases or metaphors or that there’s a logical/historical explanation to prefer one or the other but the fact remains that you can’t predict which preposition to use from the common mental picture of a book on a table vs. a book in a box.
Ok, but at least when talking about position (the “main” meaning), it’s clear that some things are on a place and some are in another; and it might eventually be confusing if, say, someone hid a painting inside a wall. If you say “en la pared” people would assume it was on the wall, hanging from it, when it’s really “in” right? What do speakers of Spanish would say then?
“Well, the Spanish speaker would tell you. That would be a strange situation, right. 99% of your paintings are on the wall. In suc a strange case we’d go out of our way to say that el cuadro está dentro de la pared. The fact that we’re unusually precise about the position stresses the fact that this is an unusual situation. In English, you’d be very tempted to say that the painting is inside the wall, not simply “in”, even if the meaning’s the same, so there’s not such a big difference”
Fair enough, you think, but the fact remains that using “in” and “on” gives a “clearer”, “more specific” picture that potentially (if not in practice) may dispell misunderstandings. I do understand and accept Spanish “lazy” approach and I see that it works in practice but insisting on being as precise as possible in all cases has a value in and of itself, right?
Now, fast forward to a different case: a German speaker learns English on Lingq. Strangely enough for the times, s/he had no previous contact with the language. That person goes on to read some sentences. S/he encounters “in the box”, well, English “in” is German “in”. Wow! That was easy. Then a book’s on a table. On the table, oh, on is “auf”, ok, Das Buch liegt auf dem Tisch. Nice!
Then, a painting’s on the wall. What? On the wall? Auf der Wand? That sounds odd. Let me get that into Google translator: “On the wall” = “An der Wand”. Hey! How did “on” change from “auf” to “an” !!! Oh, my1
Because it so happens that German makes a point of distinguishing between things that rest on surfaces and things that hang from them, lying flush next to them vertically.
The German speaker’s quite bemused, s/he tells you: “But, say that you’re thinking about a wall outside a house, a city wall or a wall in a half demolished building with no roof. The painting could be placed on top of the wall, not hanging from it, if you say “on” the wall, it’s not clear what you mean. This is way worse than in Spanish! At least there you know that “en” is a general, “vague” preposition for place. In English you pretend to be precise and then go on to use the “on” prepositon in an ambiguous way which is, arguably, the opposite of its general meaning. After all. A book standing on top of wall with no roof on it is more similar to the “book on the table” picture than a painting hanging from the wall”.
You might feel strange listening to this idea because you do appreciate the difference and you do favor precise prepositions, after struggling with the lazy Spanish “en” but you’ve been speaking English for a couple decades and never had any problem with your ambiguous, self-contradictory “on” and it had never occurred to you to ask whether “on” meant “on top of” or “hanging from” and you’d never felt like you lacked info.
The takeaway is: Different languages have different criteria to decide what information to state and what to imply in different situations. Native speakers feel that their language displays the “natural” categorization but it’s really completely arbitrary. After all I’m (almost, not quite) certain that no natural language has a nice, two-letter preposition or case ending for “a painting nailed diagonally across a wall but whose left lower corner protrudes, so as to partially obscure the door frame”
One last but very important point for you, as a Spanish learner. Don’t let these examples mislead you into believing that Spanish makes less distinctions than English. You’ll find that you’ll get used very soon to the “en la pared” and similar cases, the real struggle happens in the opposite cases: when Spanish speaker insist on stressing differences that the English language usually takes for granted and just skips unless in special cases".
Spanish considers that being a particular kind of being (belonging in a category) is very different from being located in a particular place, so that each situation deserves its own simple, common everyday verb. In English, you are a New Zealander and you also are in the park. That doesn’t make sense in Spanish. Tú eres un neozelandés pero estás en el parque. And taking it a step further, it’s not the same to be a happy person, that is content with his/her way of life (similar to being a New Zealnder) than being momentarily happy for something that just occurred (being in a happy state, similar to being in the park): ¿Eres feliz o estás feliz?
Spanish also has different tenses for when you used to do something or did it repeatedly or for a stretched period of time vs. when you did it at once, in a go and was done with it, and so on.
When you find out about these cases, you’ll feel the opposite to the “en la pared” case: “This is really splitting hairs, what’s the point of stressing this info? Trust me as a speaker to bring it up when it’s necessary but don’t torture me to think about all that everytime I open my mouth”.
These are only some examples of how languages differ from one another, there’s much more. I know, it sounds overwhelming, impossible. All language learners (even those of us who have already learned other foreign languages) often feel that it’s an impossible task. Just remember:
It is possible. Your brain’s hard wired to learn strange and completely different ways to make sense of the world. Just give it a chance. Feed it all that strangeness without too much second guessing and go on and on. Sooner than you think, everything will feel natural.
Again, good luck!