1) для описания действия, которое происходило в определенное время в прошлом. i was sleeping at 8 p.m. yesterday. 2) для описания двух или более действий, происходивших одновременно в прошлом и при этом они были в процессе. he was reading while his brother was watching tv. 3) для описания действия, которое происходило в прошлом и которое было прервано другим действием. past cont. употребляется для описания действия в развитии/процессе, а past simple – для описания действия, которое прервало его (краткое действие). he was reading a book when the phone rang. примеры

As for me and my family, we consider New Year’s a family holiday and always spend it together. We start preparing for this very carefully, usually several days before the celebration. It’s always very important to choose the right presents for the whole family and friends. Generally, we tell each other what we want for a gift, but sometimes we give each other surprise presents. It is my favorite part of the New Year’s preparations because I like to look out for perfect gifts for my family.

In the middle of December, we buy a New Year’s tree, which we decorate with my parents. It’s a tradition because it brings us together and we really have fun doing it. Also, before New Year’s Day, we always clean the house and create a festive atmosphere. I like to decorate the house with paper snowflakes, candles, and garlands.