The current study investigates the limited attainment of adult language acquisition in terms of an associative learning phenomenon whereby earlier learned cues attentionally block those that are experienced later. Short- and long-term blocking are demonstrated in experimental investigations of learned attention in the acquisition of temporal reference in a small set of Latin phrases. In Experiment 1, previous experience with adverbial cues blocks the acquisition of verbal tense morphology, and, in contrast, early experience with tense blocks later learning of adverbs. Experiment 2 demonstrates long-term transfer effects: Native speakers of Chinese languages, which do not exhibit verb tense morphology, fail to acquire inflectional cues when adverbial and verbal cues are equally available.