thejapanesepage.com/te-iru-te-aru-te-oku-te-shimau/
Explains the four common te-form endings (ている, てある, ておく, てしまう) by showing how each one changes the meaning of an action, with example sentences and audio for learners at intermediate level.
GrammarTe-formJLPT N4Example sentencesJLPTJLPT N5FreeBeginner