Subordinating conjunctions in time clauses

Read this first: https://dictionary.cambridge.org/us/grammar/british-grammar/conjunctions-time 

https://www.englishpractice.com/improve/subordinating-conjunctions-time-place/

https://www.gingersoftware.com/content/grammar-rules/conjunctions/conjunction-exercises

https://www.englisch-hilfen.de/en/exercises/word_order/conjunctions3.htm

https://wordwall.net/resource/23687054/english/time-conjunctions