Intonation can be analyzed, in part, in terms of the phonologic feature breath group. The results of an experiment are discussed in which subglottal air pressure and lung air volume were measured as functions of time for four speakers, in addition to the acoustic signal. These data show that the unmarked or “normal” breath group of American English is characterized at the articulatory level by a relatively steady tension of the laryngeal muscles throughout a single‐bounded expiration of air from the lungs. At the end of phonation, the subglottal air pressure falls and hence the fundamental frequency also decreases repidly. The intonation pattern that is a consequence of this breath group is, of course, the one that has been described as characteristic of declarative sentences and numerous other languages. The marked breath group is differentiated at the articulatory level by an increase in the tension of the laryngeal muscles at the end of phonation, which counteracts the falling subglottal air pressure to produce a not‐falling terminal fundamental frequency contour. The intonation pattern of the marked breath group is the characteristic intonation pattern of the “yes‐no” question in English and other languages.