Children manifest difficulties in sentence comprehension, which may stem from an immature competence system and/or an immature performance system. This thesis examines children's syntactic knowledge (competence system), as well as processing abilities (performance system) involved in sentence comprehension. A series of six experimental studies with French-speaking children and adults were conducted. The investigations evidenced adultlike, rule-based syntactic knowledge of word order and movement before age 2. However, the syntactic processing mechanisms of incremental parsing and revision appeared to develop beyond age 5–6, reaching adultlike performance only around age 7–8. Importantly, domain-general cognitive control abilities, namely inhibition and working memory updating, were also found to be linked to comprehension performance in both children and adults. In conclusion, the results are interpreted as evidence for a child-adult continuity in terms of syntactic competence and comprehension difficulties are attributed to children's linguistic and non-linguistic processing abilities under development.