* Phonetics is the foundation of phonology: Phonetics deals with the physical production and perception of speech sounds. It provides the data that phonology analyzes and organizes. Without understanding the acoustic and articulatory properties of sounds, it's impossible to understand how they function in a language.
* Phonological rules are based on phonetic features: Phonological rules describe how sounds change and interact in a language. These rules are based on the phonetic features of sounds, such as place and manner of articulation. For example, the rule of aspiration in English (e.g., /p/ becomes [ph] at the beginning of a word) relies on the phonetic distinction between aspirated and unaspirated sounds.
* Phonetic analysis informs phonological analysis: Phonetic analysis can help identify patterns in language that might not be obvious on the surface. This information is crucial for understanding the underlying phonological structure of a language. For example, phonetic analysis can reveal that two sounds that are spelled differently may actually be pronounced the same way, indicating a phonological merger.
In summary, phonology is a study of sound systems, and phonetics is the study of the sounds themselves. While phonology examines abstract sound systems, it relies heavily on the concrete data provided by phonetics.
Think of it this way: you can't study the rules of a game (phonology) without understanding the pieces and their movements (phonetics).