I'm not the best at Spanish, but for number 15, it is ella tiene hambre.
Answer:
I sing a lot of music.
I learn a lot in history class.
You play the guitar.
We write in the note books.
We buy the books.
I put the books in the backpack.
My friend leaves at eight o'clock in the evening.
My teacher speaks spanish.
We read many books.
You open the dictionary.
Explanation:
The way you layed out this question confused me, so i may be wrong on some.
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.
The answer would be 23:30