Теория:
Study some signal words for Past Perfect.
Words for Past Perfect:
before — перед тем как, до;
after — после;
already — уже;
just — только что;
for — в течение;
since — с тех пор;
till/until — до тех пор;
by the time — к тому времени;
never — никогда;
earlier — ранее;
when — когда;
yet — ещё не.
Examples
She knew how to cook a cake because she had made it earlier.
Рис. \(1\). Cake
James easily won this game because he had played it many times before.
Рис. \(2\). Winning a game
John had sat to work when his boss called for him.
We had already bought a cake when Jill called us and told that she bought a cake too.
I hadn’t served the table yet when the guests came.
Источники:
Рис. 1. Cake, 2016, https://pixabay.com/images/id-1850011/ Pixabay License CC0 Free for commercial use No attribution required
Рис. 2. Winning a game, 2014, https://pixabay.com/images/id-593313/ Pixabay License CC0 Free for commercial use No attribution required