In German, we are learning present perfect tense. According to the book, typically a past tense is used with the auxiliary verb haben, as so:
Du hast das gut gelernt. (You have learned that well.)
However, some verbs use sein instead; to be so the book states it must be intransitive and express a change of place or condition, like so:
Wir sind nach Hause gegangen. (We went home.)
Er ist müde geworden. (He got tired.)
However, something that always confused my teacher is the past tense of bleiben (to remain/stay). This seems to be expressing the opposite of the rules because it is not changing.
My theory on this is that it's similar to how sein is in the way that it's talking about state. Also, because it's past tense, it displays change in condition in the sense that though the subject was staying in the past, they are no longer now. However, I'm not sure if this is the true reason for it since I'm not a native speaker. Could someone more acquainted with the language explain why this is so?
(Excerpts are taken from the textbook "Wie geht's?", ninth edition.)