Columbia subject headings:
Communication in education.
German language--Auxiliary verbs.
German language--Modality.
Teacher-student relationships.
Harvard subject headings:
Communication in education.
German language--Auxiliary verbs.
German language--Modality.
Teacher-student relationships.
Princeton subject headings:
Communication in education.
German language--Auxiliary verbs.
German language--Modality.
Teacher-student relationships.