What does the suffix -pnea indicate?

• A. Breathing
• B. Air, lung
• C. Foot
• D. Forming

Answer: (A)

The suffix -pnea signals breathing or respiration. It’s used in terms that describe how a person is breathing, or whether breathing is occurring at all. For example, apnea means no breathing, dyspnea means difficult breathing, and tachypnea means rapid breathing. The element comes from Greek and is tied specifically to the act of breathing, which is why it fits this word part. Other options point to air or lung (pneumo/pneumon-), foot (ped-), or forming (various other morphemes), so they don’t match the meaning conveyed by -pnea.