Vocabulary growth from 2;0 to 3;0 was studied in 28 late talkers using
expressive vocabulary inventories reported bimonthly on the Language
Development Survey (LDS). Group milestones were 18 words at 2;0,
89 words at 2;6, and 195 words at 3;0. A sub-group of 11 children
(Group 1) showed a rapid vocabulary spurt between 2;2 and 2;8,
reached the 150–180 word mark by 2;6, and attained the LDS ceiling of
about 300 words by 2;10. In contrast, the 17 children in Group 2 still
had a mean vocabulary of fewer than 30 words at 2;6, had less of a
vocabulary spurt when they did start acquiring words, and attained the
150–180 vocabulary mark at 3;0. All 3;0 language outcome measures
were significantly predicted by LDS vocabulary size from 2;2 to 2;4.