Breakdown of Hay una fuga en el baño, es decir, el piso está mojado.
una
a, an (feminine)
en
in / on / at
estar
to be (location/state)
haber
to be (there is / there are)
Questions & Answers about Hay una fuga en el baño, es decir, el piso está mojado.
How exactly does es decir work here, and could I use o sea instead?
Es decir translates to "that is to say" or "in other words." It connects the first idea (the leak) to its practical consequence or explanation (the wet floor). You can absolutely swap it for o sea here. O sea is very common in everyday spoken Latin American Spanish, while es decir sounds just a tiny bit more formal, making it great for both speech and writing.
Does the word fuga only mean a water leak?
No, fuga literally means an "escape." While it perfectly describes a water or gas leak (una fuga de agua or una fuga de gas), it is also the word used for a literal escape, like a prison break.
Quick reminder: why do we use está in está mojado instead of es?
I have learned suelo for "floor." Why does this sentence use piso?