I need help on how you say "big sister" and "little sister."
Does anyone know?

imouto-san: little sister
onee-san: big sister

onee-san or aneue : big sister
imouto-san: little sister

Origato gozai imash!
(I hope I spelled that right...)

thatgirlroxx22 wrote:
Origato gozai imash!
(I hope I spelled that right...)

the romanized spelling is usually "arigatou gozaimasu"

also there are several ways to shorten the term for "older sister" (i dont know if this also applies to "little sister" )

Nee-san
Nee-chan
Onee-sama
Nee-sama

these are used often to show what kind of relationship the sisters have.
Nee-chan is the most informal and is used usually to show a close bond

Nee-san and Onee-san are slightly more formal but still informal enough for close sisters.

Onee-sama is usually used when there is a need for formality and respect.

Nee-sama is often used to express extream respect and idolization in a closer sibling relationship.

this is just a brief run down of the ways to use these terms however if you cant decide which is appropriate Onee-san will almost always suffice.

Rikayu wrote:
onee-san or aneue : big sister
imouto-san: little sister

Just pointing out that "imouto-san" would actually refer to someone else's little sister, not your own. Your own little sister does not have any suffix, as far as I know. I think imouto isn't used so often, since a younger sister is lower in hierarchy than you are, you'd more likely use the sister's own name, where as with older siblings you'd want to be more polite and refer to them as "older sister" or "older brother".

Onee-san's the one used most often, Aneue is a really formal way to call your own older sister. It depends on the level formality you wish to use, too.