i) Σιγά το ταβάνι
These are not idioms on their own merit. It's the use of σιγά expressing irony. One possible translation would be:
--How is this a ceiling?
Not necessarily for the first one, Helle. It could also mean: Watch for the ceiling! (or, in another context: go slowly, here comes the ceiling). We would need context to be sure, Theseus.
Yep, context, please.We would need context to be sure, Theseus.