This paper reports the results of an experiment with 21 Italian children (age 2;8-5;11) and 29 U.S. children (age 2;7-5;9) who were tested on their knowledge of verb raising to C in main WH-questions, an obligatory movement process in adult Italian and English. Along the lines of recent movement and feature checking theories, it is proposed that, in addition to morphological features, verbs have a modal feature, which has to be checked in C. One such modal feature is [+WH]. In adult Italian and English main WH-questions, [+WH] on V is checked in C overtly, and thus V raises to C in the syntax. The result of a picture ID task show that, in contrast to adults, Italian and English speaking children allow main WH-clauses without verb raising until the age of about 3;9. Evidence shows that initially, Italian and English speaking children's verb Tense is underspecified. This fact implies that the verb is not forced to move to T, and the Head Movement Constraint prevents the verb from moving to C. Thus, [+WH] on the verb can only be checked at LF in early child language. The transition into adult language occurs when the Tense feature on the verb is fully developed and thus needs to be checked in T. From there, the verb is allowed to move to C, and in fact, must move to C, in order to check [+WH] overtly. (Contains 59 references.) (Author/CK)