Sets of sounds that are similar often pattern together: similar, and sometimes act as one a set of rules, systematic share one or more features rules not to individual sounds but to categories of sounds. Slide 5: consonants: share similar sounds in the same category (3) vowels, other feature categories (4) affected by rules / processes, change pronunciations in the presence of others. Come up with features that define these sounds to the best possible answer. To define both: noncontinuants = both (oral and nasal) stops. Obstruction of airflow in the oral cavity. Opposite: continuants = continuous airflow out of the mouth. = all other consonants and vowels fricatives, liquids, etc Picture of nasal sound: nasal = space of back of mouth and velum the air is stopped at the oral cavity. Slide 12: need to know these terms because they behave together in phonetical rules top = obstruent"s, bottom = sonorants.