Question

She should have donated her time so she could help others. What are the helping verbs in the verb phrases?

a. could, help

b. should, have, donated

c. should, have, could

d. donated, help

Answer 1

The answer is: 
c. should, have, could
In English Literature, Helping verbs refer to the verbs that help other verbs to extend its meaning in the sentence, explain the mood in the sentence or add additional details on time. Helping Verbs usually only used in Complicated Tenses