Children with specific language impairment (SLI) and their MLU-matched normally developing (ND) peers imitated proper nouns, the pronouns he and you, and the article the in subject phrases. Although all of these word types were phonological phrase-initial syllables, the proper nouns received strong stress, but the function words received weak stress. Both groups of children showed significantly more omissions of the function words than the proper nouns. There was no significant difference amongst the imitations of the two pronouns or the article; all were omitted frequently by both groups. This suggests that the status of subject articles and pronouns as weak syllables in the initial position of phonological phrases may in some cases constitute a more important factor than the distinctive grammatical roles they play. A phonological explanation of subject article and pronoun omissions is explored.