WORDS WITH ER / IR / UR in the 1ST SYLLABLE
Sort words that have an er in the 1st syllable like "nervous" under ER.
Sort words that have an ir in the 1st syllable like "thirty" under IR.
Sort words that have a ur in the 1st syllable like "sturdy" under UR.
Sort words that don't fit any category under Oddballs.
CATEGORIES: ER IR UR Oddballs
nervous - thirty - sturdy - firmly - person - purpose - perfect - further - dirty - hurry - birthday - certain - spirit - mermaid - Thursday - perhaps - turtle - thirsty - birdbath - service - furnish - during - merry - purple