Acquiring the First Words by Persian Toddlers: A Longitudinal Study Using the MacAuthor-Bates Inventory

Introduction: A robust vocabulary improves all areas of communication. Vocabulary is critical to a child’s success to think and learn about the world. Expanding a child’s knowledge of words provides unlimited access to new information. This study describes the early development of comprehension and production vocabularies in a group of Persian-speaking toddlers. Materials and Methods: The mothers of 33 typical, Persian-speaking toddlers during 6 months (from 12-14 months to 19-21 months) completed the Persian McArthur-Bates communicative development inventories 7 times per month. The collected data were analyzed via the SPSS software, version 21, through non-parametric tests. Results: The results indicated that the only significant increase for both vocabularies was between 15 and 16 months (P comprehension=0.045 and P production=0.027). The development of phrase comprehension showed significant increases during six months (P<0.001). Further analysis of production vocabulary growth demonstrated the word spurt in each child (in different months and with different word levels). According to the figures, the composition of vocabulary production was different during the selected 6 months. Nouns were the largest group during the 50-, 100-, and 200-word stages; however, verbs presented a faster rate of development. Both genders showed significant changes during follow-ups (P<0.001) and there were no significant differences between the vocabularies of different genders (P>0.05). Conclusion: Persian-speaking children follow commonalities of lexical development reported for different languages; however, few differences could be traced between these children and their peers from other languages.