ㄴ다고 알다

as far as I know, it's so

-ㄴ다고 알고 있다 is 'my understanding is that' — you state something while flagging it as second-hand and open to correction. Seven of these eight lines are that: where someone lives, how an account is run, what a rule requires, how large a debt is coming. It is safer and more polite than stating the fact flat out. The first line is unrelated — a proverb about seeing as much as you know.

Register: careful, polite hedging