These sentences can be complete in the following way:
1) Nadie.- this would mean that you do not know anyone.
2) Ningún- it makes reference to the book. you do not have a book
3) nunca. This means that you do not do that activity. you never do it
4) ni. not having one thing nor the other.
5) nada. this means that the table is empty- nothing on it.
Answer:
Think about it like male and female articles.
Explanation:
If the word ends in a then the answer will be "la". That's the female article. If the word ends in o then the answer will be "el". That's the male article. "Los" is also a male article and "las" is also a female article. Those are the basics of Spanish articles.
