sion

Core Rule

-sion is a common noun suffix, pronounced /ʃən/ or /ʒən/. After voiceless sounds like t or s, it tends to be /ʃən/; after voiced sounds or vowels such as n, r, l, it shifts to /ʒən/. This reflects morphological and historical sound change.

Articulation Guide

For /ʃ/: tongue near the alveolar ridge with steady airflow. For /ʒ/: same position with vocal cord vibration. The /ən/ is weak and reduced.

Word Analysis

collision /kəˈlɪʒən/: voiced environment → /ʒən/. conclusion /kənˈkluːʒən/: consistent voiced pattern. diversion /daɪˈvɜːʒən/: r before sion triggers /ʒən/.

Pitfalls

Avoid spelling-based /sɪɔn/. Distinguish -sion from -tion and -ssion, which follow different patterns.