How do infants bootstrap initial lexical and syntactic acquisition? What are infants’ early morpho-syntactic representations? According to the classic view, preverbal and early verbal infants lack grammatical knowledge. I will discuss empirical findings that demonstrate that infants begin to perceive and represent functional elements from the first year of life, long before they are able to produce these items. Furthermore, I will show that infants use function words and prosody for acquiring lexical and grammatical representations.