1. We can help their son and daughter.
2. We can help their daughter and son.
(Which one is generally used?)
3. This is a blouse and that is a shirt.
4. This is a blouse but that is a shirt.
(Which one is grammatical?)
5. I like English or Korean.
6. She is pretty or kind.
7. They are desks or chairs.
(Are the three sentences grammatical?)
1 is used far more often than 2.
3 and 4 are both fine.
5 - 7
All are fine.