"Yn y pwll nofio"
Translation:In the swimming pool
Does this always mean in the actual water? Or can it also just refer to a building where you can swim?
Hmm... In English, 'in the swimming pool' tends to mean 'in the water', whereas 'at the swimming pool' would tend to mean in/at the place housing the pool. In Welsh we use yn for both 'in and 'at' in this context.
I have added 'at the swimming pool' as an alternative English translation.