Pointing to a tree, young Ramal says, "bird flied away." Ramal's inaccurate use of the "ed" word ending shows that he is trying to learn the _______ rules of language.

Ramal's use of "flied" instead of "flew" indicates that he is experimenting with and trying to understand the rules related to word formation and structure in language, specifically the formation of past tense verbs. This phenomenon is part of morphology, which focuses on the internal structure of words and how they can change form, such as applying regular past tense endings (like "-ed") to verbs.

Young children often overgeneralize grammatical rules they have learned, leading them to apply regular morphological patterns to irregular verbs. In this case, Ramal understands that verbs typically can take an "-ed" ending to indicate past tense, but he has yet to learn the exceptions for irregular verbs like "fly." This demonstrates his developing understanding of morphological rules in language acquisition.

The other options relate to different aspects of language: phonological rules pertain to the sounds and pronunciation of words, syntactical rules focus on sentence structure and grammar, while semantic rules deal with the meanings of words and sentences. While Ramal is working on several aspects of language development, the focus on the use of "-ed" suggests that the correct interpretation is related to morphological rules.