What age range is described as significant for developing complex grammar comprehension?

The age range from 6 to 11 years is significant for developing complex grammar comprehension because during this period, children are typically in the concrete operational stage of cognitive development according to Piaget. This stage allows for an understanding of more complex grammatical structures as children's cognitive abilities expand. They begin to grasp the rules of language more intricately, including the use of conjunctions, clauses, and varied sentence structures.

As they engage in more sophisticated conversations, read diverse texts, and receive explicit instruction in language arts, their ability to understand and produce complex grammatical forms significantly increases. This developmental milestone also coincides with their increasing exposure to formal education, where structured grammar instruction is often introduced.

In contrast, the age ranges mentioned in other options do not align as closely with this specific aspect of grammar comprehension development.