How should I use honorifics?

Question

I'm new to the Japanese langauge and currently learning about honorifics to address family members, close friends, etc.

I just have a few questions:

1. Can you use "-san" for both males/females?
2. Is "-sama" only used for males? Can you address females as "(Name)-sama"?
3. When would you use "Nii-chan" or "Nē-chan"?
4. What is the difference between O-kāsan and Kāsan?

(These are confusing to me)

Answer 1

1. Yes, you can absolutely use "-san" for both males and females.
2. "-sama" can be used for both males and females. It is a degree of politeness higher than "-san", so realistically you will not be in situations where you are required to use it.
3. You can use "Nii-chan" or "Nee-chan" with someone who is an older brother or older sister-type figure to you, whether that be an actual sibling, an older friend, or a host brother/sister. "-chan" is a less formal, cutesy version of "-san", so you should only use it if you have a very closer relationship to the person you are addressing. "O-nii-san" and "O-nee-san" are also commonly used, so I would use those if you aren't sure if the person you are talking with is okay with you refering to them as "Ni-chan" or "Nee-chan". And lastly, "Ni-chan" is for older brother/male friend, "Nee-chan" is for older sister/female friend.
4. the "O" in "O-kaa-san" is an honorific, so "Kaa-san" is slightly less formal than "O-kaa-san". To be safe, if you are referring to your host mom or someone else's mom, you should use "O-kaa-san", ESPECIALY if it is someone else's mother.