Which aspect of language development includes understanding syntax?

The correct choice is grammatical development, which encompasses the understanding and use of syntax—the set of rules that govern the structure of sentences. When children acquire language, they learn how to combine words in a way that follows grammatical rules, such as word order and sentence structure. This learning process is vital for effective communication, allowing children to form complex sentences that convey precise meanings.

Grammatical development also includes other elements of language, such as morphology (the structure of words) and the ability to use different tenses, which are essential aspects of language proficiency. Children gradually become aware of how various sentence structures can change the meaning and create more nuanced communication. As they develop their grammatical skills, they move from simple phrases to more structured sentences that reflect an understanding of syntax.