at a zero-to-eighteen-month level of a typical development (article use)

[Alexey86]

Okay, good. That's my point too. I hope we've gotten somewhere.

Definitely and... unfortunately, because this is the very point where I'm stuck. When I think about English levels, I can imagine only one 'building' we, learners, all live in. I understand that this picture misleads me, but I just can't think of more than one now. Maybe I just need some time to process all this information.

[GoesStation]

And my answer would be "He's on the second floor". A man can only be in one place at one time. Your question does not need to elicit the information that we're talking about the building on the right because that's where we can see him. That building has only one second floor.

I'm not asking about the floor of that building. There are five buildings in the picture (I mistakenly wrote on the picture earlier) and, therefore, five second floors. The man is on one of these five = He's on a second floor. This is all my question is about.

The answer to the question is, as emsr2d2 said, "He's on the third floor" (in American English). No native speaker would use the indefinite article regardless of what you think. Just accept that and move on.

[Alexey86]

Maybe I just need some time to process all this information.

I've thought it over and come up with an explanation. I'm not saying it's universal or exhaustive.

Temperatures and levels are parts of open-ended structures. You can always add one more degree or develop your command of any language. Floors, on the other hand, are mostly parts of closed structures:



A building under construction can be considered an open-ended structure, which allows me to tell somebody the news that I've build a second floor. To be clear, open-endness is not an inherent feature of such a building itself. It's all about the listener's knowledge. If the listener already knew the second floor was under construction, it would become part of a closed information structure.

[Piscean]

which allows me to tell somebody the news that I've build a second floor. .

The trouble with that is that we say 'the second floor'.

You're fighting a losing battle, Alexey.

[Alexey86]

The trouble with that is that we say 'the second floor'.

https://steamcommunity.com/app/24276...4736003700110/

https://ludwig.guru/s/built+a+second+floor

You're fighting a losing battle, Alexey.

I'm not at war with anyone.

[emsr2d2]

No one is saying that it's not possible to put the words "a", "second" and "floor" in that order in a sentence, but we are talking about your original context. It remains the case that when describing someone's location, we say "on the ground/first/second etc floor".
None of the examples you linked to are preceded by a preposition. The second link goes only to the hits for "build a second floor". If you remove "build" and simply search for "a second floor", you will notice that none of the example sentences include "on a second floor".

[Charlie Bernstein]

The trouble with that is that we say 'the second floor'.

You're fighting a losing battle, Alexey.

I have no problem with Alexey's "I've built a second floor."

But I'd rather advise on ordinary written or spoken usage than thumb-wrestle over exceptions. This is English. There are exceptions to everything.

[Alexey86]

The second link goes only to the hits for "build a second floor". If you remove "build" and simply search for "a second floor", you will notice that none of the example sentences include "on a second floor".

I've found such examples:

1. Fifty workers and customers huddled for safety on a second floor as it was raked with bullets.
https://www.nytimes.com/2004/07/16/w...ists-rise.html

2. The clinic is not more than a warren of rooms on a second floor that is reached only by stairs, making it a daunting climb for weakened patients.
https://www.nytimes.com/2003/05/18/w...nt-denial.html

3. He said police first photographed him for a biometrics database, took him down a long cinderblock hallway on a second floor, and handcuffed him to a bench bolted to the floor.
https://www.theguardian.com/us-news/...are-black-site

This is English. There are exceptions to everything.

I really prefer the word explanation to exception.

[Charlie Bernstein]

Those are all good examples, Alexey. I think you've answered your own question. You're right. Sometimes using a is correct.

I'm satisfied with that. Well done!

[Piscean]

You're fighting a losing battle, Alexey.

Well, Alex proved me wrong. I am normally pretty good at coming up with rare contexts, but I failed this time.