I don´t get te meaning of

[gitom]

En un pis no sabem quin
h iva viure Moratin.
Could anyone give an explanation?

[poli]

This website focuses on Castilian, but anyone who knowd\s some Castilian has, at least, clue. I think it may means they don't know what floor Moratin lives on. Have you tried a translation website?

[JPablo]

En un piso, no sabemos cual,
vivió Moratín...

At an apartment [flat], we don't know which,
is where Moratín lived...

[gitom]

It was the missing comma, that misled me to the troubles of nowhere, me being a German speaker. So I translated happily away: " In a chamber we don´t know..." ? :confused:

[JPablo]

Well, that was not too far off...

You could also say "En un piso del que no sabemos nada" (At an apartment of which we do not know anything...)

Are you learning Catalan?