1. which sentence contains an error in subject-verb agreement? elke or carina is going to be the new dance squad captain. july and august are the warmest months of the year. each volunteer and staff member need to arrive at the scheduled time. some of her friends and family members are coming over for dinner. which sentence contains an error in subject-verb agreement?

Each volunteer and staff member need to arrive at the scheduled time.

Explanation:

The adjective each is used before a singular countable noun, and, therefore, the verb should be singular, too.  

So the sentence should be written as "Each volunteer and staff member needs to arrive at the scheduled time."

All the other sentences contain no errors in subject-verb agreement.

may i see the historical information and the excerpt?