Singular versus plural rules: |
Rule one: |
| Terms that end in “a”, for plural add an “e”. Example: vertebra (singular), vertebrae (plural). |
Rule Two: |
| Terms that end in “is”, for plural change it to “es”. Example: diagnosis (singular), diagnoses (plural) |
Rule Three: |
| Terms that end in “ex” or “ix” for plural replace with “ices”. Example: cervix (singular), cervices (plural) |
Rule Four: |
| Terms that end in “on” for plural replace it with “a”. Example: criterion (singular), criteria (plural) |
Rule Five: |
| Terms that end in “um” for plural replace it with “a”. Example: bacterium (singular), bacteria (plural) |
Rule Six: |
| Terms that end in “us” for plural replace it with “i”. Example: bronchus (singular), bronchi (plural) |
Rule Seven: |
| Terms that end in “itis” for plural replace it with “itides”. Example: arthritis (singular), arthrides (plural) |
Rule Eight: |
| Terms that end in “nx” for plural replace it with “nges”. Example: phalanx (singular), phalanges (plural) |
Rule Nine: |
| Terms that end in “y” for plural replace it with “ies”. Example: therapy (singular), therapies (plural) |
Rule Ten: |
| Terms that end in “x” for plural replace it with “ces”. Example: thorax (singular), thoraces (plural) |
| [ 1 ] Quick Introduction.
[ 2 ] Word Building Reference (See below): [ 3 ] Medical Terms – Singular versus plural rules [ 4 ] Medical Terminology Exams [ 5 ] Medical Terms – Prefixes, roots, suffixes (Reference). |
This is a great reference to help strengthen your understanding of medical terminology. See how common medical terms are created using the various prefixes, suffixes, and root words.
Increasing your understanding of medical terminology
Word Building Reference– This resource strengthens your understanding of medical terminology. See how common medical terms are created using the various prefixes, suffixes, and root words.
Medical Terminology Intuitive Section 
This section was developed for ‘speed learning’ of medical terminology.
Additional references:
Prefixes denoting numbers
Prefixes denoting position and/or direction
Prefixes denoting measurement
Medical Terminology Noun Suffixes
Combining forms for color
Common Prefixes
Adjective Suffixes
Specialties and specialists med terms
Instruments, surgical, and diagnostic procedures
Negative prefixes
Common suffixes
Quick Introduction– provides an overview and introduction to medical terminology.
Medical Terms – rules governing singular versus plural versions of medical terms are described.
