answersLogoWhite

0

'Sis' is much more informal than 'sister', so you would not use 'Sis' in referring to her to others outside the family, in making introductions, in writing, at work, at formal events such as weddings or funerals.

Depending on the standards of your family, it may also not be acceptable at family dinners or anywhere in public. Also, regardless of the occasion, it is only OK if your sister does not mind being called Sis.

User Avatar

Wiki User

16y ago

What else can I help you with?