-sion ending

Core Rule

Words ending in -sion are typically nouns of Latin origin. The ending is pronounced /ʃən/ or /ʒən/ depending on voicing. After voiceless sounds (often t), -sion surfaces as /ʃən/; after voiced sounds (d, s, z), it often becomes /ʒən/. The spelling remains stable while the vowel reduces.

Articulation Guide

For /ʃən/, raise the tongue toward the post‑alveolar ridge, keep lips slightly rounded, and let the airflow pass smoothly. For /ʒən/, maintain the same position but activate vocal cord vibration. The -ion vowel is reduced to schwa /ə/.

Word Analysis

• equation /ɪˈkweɪʒən/: historical t + ion leads to voicing and /ʒən/.
• exposure /ɪkˈspoʊʒər/: not spelled -sion, but the -sure ending shares the same /ʒ/ sound, reinforcing the pattern.
• glacier /ˈɡleɪʒər/: spelling differs, yet the soft /ʒ/ illustrates morphological sound shifts beyond letters.

Pitfalls

Do not pronounce -sion as /sɪon/. Avoid stressing the final syllable. Distinguish -sion from -tion and -cian, which follow different triggering rules.