This is the 155th most frequent German word.
frage
Question
Here, 'Frage' is used as a noun meaning 'question', referring to a query seeking information.
Das ist eine schwierige Frage.
This is a difficult question.
In this sentence, 'frage' is used as a verb, 'fragen', in the first person singular ('ich frage mich'), meaning to inquire or wonder internally.
Ich frage mich, ob er heute kommt.
I am wondering if he will come today.
In this example, 'Frage' is used as a noun referring to an inquiry that is intended to be directed to someone, here specified as the teacher.