德语双重或者可变前缀

Dual or Variable Prefixes Separable/Inseparable Prefixes (Can be either one or the other)
Prefix	Meaning	Examples
durch-	through	durchdringen (sep., penetrate) durchfahren (sep., drive through) durchfressen (insep., eat through [acid, rust, etc.])
hinter-	behind	hinterlassen (insep., leave; bequeath) hinterlassen (sep., allow s.o. to go behind)
über-	over, across	überfahren (insep., run over) überfahren (sep., ferry across, cross over) überfallen (insep., attack, hold up [a bank]) übersetzen (insep., translate) übersetzen (sep., ferry across) überwinden (insep., overcome)
um-	around	umarmen (insep., embrace, hug) umbauen (sep., renovate, convert) umbauen (insep., enclose, surround) umbinden (sep., tie on) umkehren (sep., turn back, turn inside out) umschreiben (sep., rewrite, transcribe) umschreiben (insep., paraphrase, outline; skate around [fig.]) umziehen (sep., move [to new residence], change [clothes])
unter-	down	unterbrechen (insep., interrupt, disconnect) unterbringen (sep., accomodate) unterdrücken (insep., oppress, repress, suppress) untergehen (sep., sink, perish) unternehmen (insep., do, undertake) unterwerfen (insep., conquer, subjugate) unterzeichnen (insep., sign [a document])
wider-	against, re-	widerklingen (sep., resound) widerlegen (insep., refute, disprove) widerraten (insep., advise/counsel against) widersprechen (insep., contradict) widertönen (sep., echo)
wieder-	again	wiedergeben (insep., restore, give back; recite, perform; represent, reproduce, convey) wiederkehren (sep., return, repeat, recur) wiedersehen (sep., see/meet again)
Note: All of the dual verb prefixes are stressed when separable, unstressed when inseparable: übersetzen (ferry across) vs. übersetzen (translate).