1. Phonetics: This is the study of the sounds of speech. It involves describing and classifying speech sounds based on their physical properties, such as how they are produced by the vocal tract (articulatory phonetics) or how they are perceived by the ear (acoustic phonetics).
2. Phonology: This is the study of how sounds are organized and used in language. It focuses on the rules that govern the distribution of sounds in a language, how sounds change in different contexts, and how they are used to create meaning. For example, it explores why some sounds are not allowed to occur next to each other in a language, or how sounds can change depending on their position in a word.
3. Phoneme: A phoneme is the smallest unit of sound that can change the meaning of a word. For example, the words "cat" and "cot" differ by only one phoneme, /kæt/ vs. /kɑt/.
4. Allophone: Allophones are variations of a phoneme. They sound slightly different, but they do not change the meaning of a word. For example, the /t/ sound in "top" and "stop" are allophones of the same phoneme.
5. Prosody: Prosody refers to the rhythmic and melodic aspects of speech, including stress, intonation, and rhythm. These features play a role in conveying meaning and emotion, and they can also affect how words are pronounced. For instance, the difference between "I'm going to the store" and "I'm going to the store?" is purely based on prosodic features.