Final answer:
Infants find it difficult to detect word boundaries because of limited phonemic discrimination skills and their stage of language development.
Step-by-step explanation:
Infants find it difficult to detect word boundaries because they can only discriminate among phonemes used in their language or languages in their environments. As they grow older, they lose the ability to discriminate among all possible human phonemes. This makes it challenging for infants to distinguish between phonemes in words and recognize word boundaries.
Additionally, infants in the early stages of language development typically use one-word utterances to convey meaning, focusing on familiar objects or events. They may not have a clear understanding of the boundaries between words yet.
Overall, the difficulty in detecting word boundaries for infants can be attributed to their limited phonemic discrimination skills and their stage of language development.