Когда надо писать did а в каких didn't

Did - повествование время)
didn't (или did not) - отрицание время)

Did пишется в повествовательных и вопросительных предложениях в времени. Повествовательное: I did homework ye
sterday. Вопросительное: Did you do homework yesterday?. В предложениях где есть did все остальные глаголы в времени пишутся без окончаний . А didn't пишется в отрицательных предложениях . Например: Отрицательное : I didn't do my homework. Как то так)

The guests have already come,but the main course hasn't been served yet.They were offered refreshments
(snack) and drinks.

Healthy eating rules are followed by vegetarians-Present Simple Passive.
The native people of the New World
cultivated corn-Past Simple Active.
Their work was begun at 7 o'clock by them-Past Simple Passive.
The practice had been done at the restaurant by our group last year-Past Perfect Passive

Some people don't have part-time jobs.
Do some people have part-time jobs?
Do some people have part- time or
casual work?
Who has part-time jobs?
What work do some people have?
Some people have part-time work,don't they?

Britney Spears - Biography of the singer in English.

Britney Jean Spears (born December 2, 1981) is an American pop singer. Her career encompasses chart-topping records, high-profile advertising and a foray into acting. Today she is considered an American cultural icon recognized throughout the world, but is also the subject of controversy surrounding the sexuality of her music and image.
Biography

Born in McComb, Mississippi and raised in Kentwood, Louisiana, Spears first came to fame as a member of the New Disney channel on the Mickey mouse club in the 1993 and 1994 seasons.

Her colleagues on the show included Justin Timberlake and Joshua Chasez (who later became members of the pop band nsync), Keri Russell (star of the TV show felicity), Christina Aguilera, also a pop singer and actor Ryan Gosling. Spears dated Timberlake for about five years.