NLP models face significant challenges in understanding idioms and metaphors because these expressions often have meanings that differ from their literal interpretation. For instance, "kick the bucket" means "to die" and not the physical act of kicking a bucket. Understanding such phrases requires cultural knowledge and contextual awareness.
Pre-trained models like BERT and GPT improve idiom and metaphor understanding by leveraging large-scale corpora that include diverse linguistic patterns. Fine-tuning on datasets rich in idiomatic expressions further enhances their performance. For example, if a model encounters "kick the bucket" frequently in contexts related to death, it learns to associate the phrase with its figurative meaning.
Challenges persist, as idioms and metaphors vary across languages and regions, and many are underrepresented in training data. Research in multimodal NLP, combining text with images or other data, shows promise in improving understanding of figurative language. Despite advancements, fully interpreting idioms and metaphors remains an ongoing area of development in NLP.