An Etymological Dictionary of the German Language/verlangen
verlangen, vb., ‘to claim, demand,’ from MidHG. (rare) verlangen, ‘to desire ardently,’ usually MidHG. belangen, ‘to desire, long for.’ OSax. langôn, Du. verlangen, AS. lǫngian, E. to long, show the correspondence of the Teut. languages. The word is usually regarded as an old derivative of lang, but this is opposed by the meaning; it might be rather compared with the cognates of gelingen, the primary meaning of which is ‘to aim, strive.’ —