How do I know when to use the subjunctive or indicative with the word 'cuando'?

'Cuando' belongs to the group of 'conectores temporales', or, words that help us to express actions in different points of time. 1. If you want to describe an action that is habitual or set in the past you use the indicative:HABITUALE.g. Cuando vamos al supermercado, siempre compramos leche. (When we go to the supermarket, we always buy milk)PASTE.g. Cuando llegué a casa, mis padres y yo cenamos.(When I arrived home, my parents and I had dinner)2. However, if you want to describe an action that will take place in the future you must use the subjunctive:E.g. Cuando sea mayor, seré profesora.(When I am older, I will be a teacher)Don't forget! 'Cuándo', commonly used to ask questions, always requires the indicative.E.g. ¿Cuándo vas a la playa?