Construction -IB QOL-
The construction "verb-IB QOL-", i.e. the past gerund followed by the auxiliary verb qol- (root meaning: 'to stay'),
expresses a change of state (transformation of quality, character, condition, etc.), which has been exhaustively completed,
and which is still of lasting relevance.
He has fallen in love.
Men charchab qoldim.
I've got tired.
Sochim oqarib qoldi.
My hair has turned white.
Soatim buzilib qoldi.
My watch has gone wrong.
Katta bo'lib qolibdi!
He has grown up so much!
He has started thinking.
Poyezd ketib qolgan ekan.
Apparently, the train has/had already left.
It has often an additional meaning of suddenness:
Chiroq birdan o'chib qoldi.
The lamp suddenly went out.
Or that the action takes place unexpectedly:
Mehmon kelib qoldi.
The guest came unexpectedly.
Men uni kutubxonada ko'rib qoldim.
I saw her unexpectedly at the library.
Og'lingiz maktabga kelmay qoldi.
Your son doesn't come to school any longer.
It may also express that the action comes timely:
He fled just on time.