Umkehren

Umkehren is a German verb with several related meanings centered on turning back, reversing, or converting. It is built from the prefix um- (back, again) and the verb kehren (to turn, to sweep), and is used in both literal and figurative contexts.

Senses and usage include:

- Reversing a direction or a process: to turn back or to reverse course. Examples include wind, movement, or developments, as in die Richtung kehrt sich um or eine Entwicklung umkehren.

- Reversing a decision or policy: to undo or reverse an stance or action, for example eine Politik oder Entscheidung umkehren.

- Religious or ideological conversion: to convert someone to a faith, or to convert oneself, as in jmdem zum Glauben umkehren or sich zum Christentum bzw. zum Islam umkehren.

Grammar and related forms:

Umkehren is a separable verb. In present tense you typically say ich kehre um, du kehrst um, er kehrt um. In the past tenses the prefix is integrated in the participle, for example er hat umgekehrt or er kehrte um. Noun forms include die Umkehr (the reversal, turning back) and related terms such as die Kehrtwende (turnaround) and die Umkehrung (reversal). Related verbs include umwandeln (to convert/transform) and umdrehen (to turn around).

See also:

- Umkehr, Umkehrung, Umkehrfunktion (in mathematics and logic)

- Synonyms: umdrehen, rückgängig machen, verändern (depending on context)

Umkehren thus covers both physical turnarounds and figurative reversals, with a common religious connotation in phrases like jemanden zum Glauben umkehren.