1. Either Akriti or her sister ____cooking today.
Because any ONE person is cooking.
Either Kriti or her friends _____ participating in the drama.
Between two subjects If the first one is Singular and the later one is plural, Verb will be placed according to the number of later one.
3. Amit and Sumit ____ practicing for the match since last night.
Two different subjects are added with AND who are individual with their own identity.
4. Hurry up ! Bullock and cart ____waiting for us outside.
Two subjects are added with 'and ' but make one sense ' BULLUCKCART '
5. Neither Aman nor Shobhit ____attending the party tonight.
no one is going and both the subjects are individual.
6. Neither Samridhi nor her friends _____crying on the farewell party.
The verb will be placed according to the number of later subjects.
7. The manager and secretary ____invited on his Birthday Party.
' THE' has been placed before the first subject only that means ( manager and secretary both are the same person)
9. The manager and the secretary ____invited on his Birthday Party.
' THE' has been placed before both the subjects that tell ( manager and secretary both are different persons)
9. A number of trees ____ been fallen down due to cyclone.
A number of + noun - when are unspecific, will take PLURAL HELPING VERB
10. A number of green trees ____ been fallen down due to cyclone.
' green trees' - specific noun - A number of + noun - when are specific, will take SINGULAR HELPING VERB