The past simple is used to express habits and stateA condition that exists at a particular time. E.g.: I am sick. This melon weighs two kilos. s that happened or existed during a period of timeThe length of time between two points of time. in the past. This period can be implied, or expressed with a time expressionA word or group of words used in a particular situation. E.g.: Good morning, at six, on the sofa or a clauseA group of related words containing a subject and a verb..

When I was a child I visited my grandma every weekend. (habit)
When my brother was young he liked spinach. (state)
Where did you go to primary school? (habit, where the implied period of time is when you went to primary school)

Diagrams

Past simple for completed actions in the past
Past simple Past simple for actions over a period of time in the past