Phonology is the study of sound systems in language. It includes units of sound like phonemes, as well as features like word stress, sentence stress, and intonation. Phonemes are the smallest units of sound that make a difference in meaning. Phonology examines the sound patterns and rules in a language. Word stress is when we give greater emphasis to certain syllables within a word. Sentence stress involves emphasizing different parts of a sentence. Intonation refers to the musical qualities and patterns of speech. Together these sound features are studied in phonology and contribute to connected speech.