sich erkundigen — to inquire, to go and find out
sich kundig machen — to make oneself knowledgeable
nachfragen — to ask again, to follow up with a question
in die Sprechstunde gehen — to go to someone’s office hours. Professors, doctors and class teachers hold a Sprechstunde, and the person with the question goes to them. A Duden example: zur Klassenlehrerin in die Sprechstunde gehen, to go to the class teacher’s office hour.
die Holschuld — the legal term for a debt that the creditor must collect. Duden gives a figurative example: Die Anleger haben eine Holschuld … und müssen sich dementsprechend informieren. “Investors have a duty to fetch and must inform themselves accordingly.”