A rule in my text book says
If the 2 subjects separated by 'and' refer to the same thing/person/suggest the same idea, they take a singular verb.
E.g. The Horse and Carriage is ready
I feel that the sentence should be -
The Horse and Carriage are ready
And Grammarly agrees with me -
So what does the subject agree with? 'Is' or 'are'?
