while
and
Structure
- Verb[stem] + つつ
硬
[Aつつ、B is used when two actions are done at the same time・Used in more formal settings]
ツバメは飛行しつつ、寝ることができる。
Based on how the grammar point was explained, this example sentence seems super, mega wrong.
Caution - Unlike ながら, つつ is used more often when the (A) action is an ongoing state, rather than an actual physical action that involves movement.
Flight is an active, physical activity which involves movement. The only explanation I can fathom is a nuance wherein the swallow being asleep makes it a non-active participant in its own flying, downgrading its flight to the “ongoing state” status of hurtling through the air.
This is some hefty nuance to be dropped in unexplained, so it feels more likely that it is an error. If this is in fact hefty nuance, please confirm! My mind would indeed be blown.