* Sub-: This is the most common prefix for "under." It's used in words like "submarine," "subway," and "subcutaneous."
* Hypo-: This prefix signifies "below" or "under" in terms of position or amount. Examples include "hypothermia" (below normal body temperature) and "hypodermic" (below the skin).
* Infra-: This prefix means "below" or "beneath," often in a structural sense. Examples include "infrared" (light waves with frequencies below those of visible light) and "infrastructure" (the underlying foundation of a system).
* Under-: This is a straightforward prefix that directly means "below" or "beneath." Examples include "underneath," "underwear," and "underestimate."
These prefixes are commonly used to create new words with specific meanings, providing a succinct and effective way to convey the concept of "under" in different contexts.