1. It is a pen. It is not a pen.||It isn't a pen.
2. Nam and Ba are fine. Nam and Ba are not fine.||Nam and Ba aren't fine.
3. She is Lan. She is not Lan.||She isn't Lan.
1. It is a pen. It is not a pen.||It isn't a pen.
2. Nam and Ba are fine. Nam and Ba are not fine.||Nam and Ba aren't fine.
3. She is Lan. She is not Lan.||She isn't Lan.