English for Today by Ganiu Abisoye Bamgbose (Dr GAB)
FEW MORE RULES
- When “and” joins complementary nouns like items of a meal, the verb should be singular:
Rice, beans and plantain ~are~ my favourite meal (nonstandard).
Rice, beans and plantain is my favourite meal. - When addition, subtraction and other mathematical indices join two nouns, the verb could be singular or plural:
Ten plus ten is twenty (standard).
Ten plus ten are twenty (standard).
GAB