Which suffix, when forming medical terms, represents 'pertaining to' and is written as -al?

• A. -al
• B. -an
• C. -ar
• D. -ary

Answer: (A)

Suffix -al signals a relationship to something in medical terms. When you attach -al to a root, it creates an adjective that means “pertaining to” that root. For example, renal means pertaining to the kidney, neural means pertaining to nerves, and nasal means pertaining to the nose. This is the standard way to express “pertaining to” in medical terminology, so -al is written as -al in these terms.

The other suffixes are used for different word-formation purposes and don’t consistently convey the exact sense of “pertaining to” in medical terms, so they don’t fit this particular meaning.