This document discusses how to use the past continuous tense to describe two actions happening simultaneously in the past. It provides examples of sentences using the past continuous to express parallel actions like "I was studying while he was making dinner" and questions asking about simultaneous past actions like "Were you listening while he was talking?". It also notes that multiple actions can be linked with commas in a single past continuous clause, like "They were eating dinner, discussing their plans, and having a good time."