grammar.verbs.reflexive-meaning-change
When se changes the meaning: ir/irse, dormir/dormirse
Adding se shifts the sense: ir (go) / irse (leave), dormir (sleep) / dormirse (fall asleep), quedar (arrange/be located) / quedarse (stay), llevar (carry) / llevarse (take away).
grammarB1✓ Reviewedv0.1.0
Explanation
Pairs to know: ir/irse, dormir/dormirse, quedar/quedarse, llevar/llevarse, poner/ponerse (put / put on, become), volver/volverse (return / turn around, become), comer/comerse (eat / eat up entirely).
The se often adds completion, change of state, or departure. With food and drink it signals finishing the whole thing: se comió toda la pizza.
The added se rarely means a literal 'to oneself'; more often it signals departure, change of state, or completion. That is why irse is 'to leave (go away)', dormirse is 'to fall asleep' (cross into sleep), ponerse + adjective is 'to become', and comerse/beberse stress polishing off the whole thing.
Examples
I'm leaving; it's late.
Region: global
The kid fell asleep in the car.
Region: global
I'm leaving now; last night I fell asleep on the sofa and drank up all the coffee.
Region: global