The Phlegmatic temperament has three combinations: Phlegmatic-Choleric, Phlegmatic-Sanguine, and Phlegmatic-Melancholic.
The traits of the primary temperament, Phlegmatic, may be altered or modified in some significant way determined by the influence of the secondary temperament. Remember, there are at least three levels of intensity of a temperament: classic, moderate, and mild. Some Phlegmatics will be very strong, others somewhat strong, and still others more mild.
Phlegmatic is traditionally understood as being fundamentally stable (defined as "weak emotions") and introverted (defined as "long-lasting emotions").