yesterday
The German word for 'yesterday' is 'gestern'. It is used to refer to the day before the current day, just like in English. For example, 'I saw her gestern' means 'I saw her yesterday'.
I saw a movie yesterday.
This is a simple past tense sentence describing an event that happened the previous day, viewing a movie.
It was very cold yesterday.
None
We played football yesterday.
This is a past tense expression showing that the speaker and some other people engaged in a game of football the previous day.