Theoretical Phonetics of the English Language is a book that discusses the phonetic system of the English language, phonetics as a science, and the connection of phonetics with other branches of linguistics. It covers the segmental and suprasegmental levels of phonetics, including the vocalic and consonantal subsystems, patterns of stress and intonation, pitch, stress, rhythm, tempo, and pauses. The book also includes a quote by Alfred Charles Gimson, an English phonetician, about the importance of phonetics in language learning.