What is causing "Bessie" to hesitate upon acceleration. on 2000 Toyota Corolla

When i start to accelerate at a stop sign/light, "Bessie" sometimes just hesitates and I'm sitting there trying to get moving. People behind me Beep their horn or yell. After a few pumps of my foot, "Bessie", will eventually get going. Then, during acceleration, she has trouble getting going. hesitation again. Whats the problem?

Asked by for the 2000 Toyota Corolla
when was bessie's last tune up?