Answer:
Todos nadamos / Todos nadan (We all swim (Todos nadamos) and You all swim (todos nadan))
Yo no (Not me or no, me would be either yo no or no yo depending on what you want to say (Can I get some context?))
A la semana
los días
nado tres veces (I swim three times (tres veces is perfectly fine))
Explanation:
All were correct depending on what you wanted to say, since I didn't get any context.
