An onset is the initial consonant sound or sounds of a syllable. For example, in the word cat, the onset is the letter c. In the word spring, the onset consists of the consonant cluster spr. Onsets can vary in complexity, ranging from a single consonant to multiple consonants grouped together. Onsets are important in phonetics and phonology, as they help in understanding how words are structured and pronounced. They play a role in language development and literacy, aiding in the recognition of patterns in spelling and reading. By identifying onsets, learners can improve their decoding skills when encountering new words.