positional variant (does not occur in isolation)
Based on Maciołek & Tambor (2012)
Voiceless: the vocal folds are separated, not vibrating, the air flows freely between them.
Labiodental: the lower lip gets closer to the upper teeth.
Palatalized: the middle of the tongue gets closer to the hard palate as a secondary articulation.
Fricative: there is a narrow passage between the articulators, the air from the lungs hits the edge of the passage and creates noise.