- a.1) John and Sam are friend.
- a.2) John and Sam are friends.
Now if you say (a.2) is correct and (a.3) then what about (b.1),
- b.1) John and Liza are couple.
Consider another example,
- c.1) John and Sam both are smart.
I want to ask you about the correct rule for such sentence construction.
If I made any grammatical mistake in the question then please mention it in comment