Previous research has shown that infants and adults can discriminate between prosodically similar languages using only prosodic cues. These experiments were designed to determine whether listeners use pitch cues or segmental duration and timing cues (i.e., rhythm cues) in language discrimination. We tested American English learning 7-month-old infants and adults on their ability to discriminate between sentences in American English and German that had been re-synthesized to isolate different cues. Infants were presented with low-pass filtered speech and speech with re-synthesized sinusoidal pitch. Adults were presented with low-pass filtered speech and two conditions where sonorants were replaced with /a/ and obstruents were replaced with silence: one contained both pitch and durational cues and the other contained only durational cues. Pitch cues were important for infants as well as adults. For infants, pitch cues were necessary for successful language discrimination; neither segmental nor durational cues were sufficient. For adults, the presence of pitch prevented listeners from discriminating English and German. Only when pitch cues were removed did adults rely on durational differences to distinguish languages. These results demonstrate that to distinguish prosodically similar languages, specifically English and German, American English listeners' weight pitch cues over durational cues.