Chain multiple て-forms; only the final verb carries tense/politeness:
The て-form of a verb can be used to connect multiple actions in sequence, indicating that one action happens and then the next follows. It functions like "and" or "and then" in English, linking events in the order they occur.
You can chain two or more て-form verbs together to describe a series of actions. Only the final verb in the chain carries the tense and politeness level for the entire sentence.
While the て-form often implies that actions happen one after another, context can sometimes allow a looser "and" connection where the strict time order is less important. However, when describing a clear sequence of steps, the order of the て-form clauses should match the actual order of events.
Because only the last verb determines the tense, the て-form clauses themselves do not change for past or polite forms.
This pattern is extremely common for describing daily routines, giving instructions, and narrating events. It is one of the most fundamental uses of the て-form.