"Jest" with the meaning of "there is"

[Destal]

Hello,

About the two following sentences:

• Kot jest na dachu.
• Na dachu jest kot.

I understand them as "The cat is on the roof" for the first one, and "There is a cat on the roof" for the second one.

To me, it is two different uses of "jest": in the first one, "kot" is subject of "jest"; in the second one, "jest" is used in a specific way that it doesn't have any subject, like in "Na zewnątrz jest słonecznie".

I've always understood things this way, until recently where my Polish teacher told me that to her, instinctively, "kot" was the subject in both sentences and only the word order changes (but still she agrees with the two different meanings).

I struggle accepting that, because the meaning is really different between the two sentences, and just changing the word order seems quite light for conveying such a difference, especially in Polish where word order can be changed rather easily, generally for insisting on things.

To me, "Na dachu jest kot" with "kot" as a subject would be for insisting on "Na dachu", like in such a situation:

• Gdzie jest kot?
• Na dachu.
• Może w kuchni?
• Na dachu jest kot! Nie słuchasz mnie?

I'd like to have some explanations please

[DmGabin]

What kind of explanation do you need? Your teacher has explained it. In the situation you described the last phrase would sound natural as follows:

Na dachu! Kot (jest) na dachu! Nie słuchasz mnie?

I struggle accepting that,

Don’t struggle. Just accept the fact that different languages are, well, different.

[Żar]

In „Kot jest na dachu.”, „kot” is the subject as well as the topic.

In „Na dachu jest kot.”, „kot” is still the subject, but „na dachu” is the topic.