5.37 Events before a particular time in the past: the past perfect

If you want to talk about a past event or situation that occurred before a particular time in the past, you use the past perfect.

• One day he noticed that a culture plate had become contaminated by a mould.
• By dusk tear gas had spread through the south campus.
• She had lost her job as a real estate agent and was working as a waitress.
• I detested any form of games and had always managed to avoid children's parties.