1. We can help their son and daughter.

Question

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?)

Answer 1

1 is used far more often than 2.

3 and 4 are both fine.

5 - 7
All are fine.