linguistic:translation
10-12 months

Infants now can no longer discriminate most nonnative sound contrasts that fall within the same sound category in their native language. Their perceptual system has been tuned to the contrasts relevant in their native language. As for word comprehension, Fenson et al. (1994) tested 10-11-month-old children's comprehension vocabulary size and found a range from 11 words to 154 words. At this age, children normally have not yet begun to speak and thus have no production vocabulary. So clearly, comprehension vocabulary develops before production vocabulary.