The -STION Rule: Why Question, Suggestion, and Digestion Sound Like 's-chun'

The Exception Hiding Inside -TION

You have probably learned that -tion says /ʃən/, like nation ("NAY-shun") and station ("STAY-shun"). That rule is reliable, with one important twist: when the ending follows an S, it becomes -stion and is pronounced /s.tʃən/, with a clear CH sound. So question is "KWES-chun," not "KWES-shun."

This is why question, suggestion, digestion, and combustion all contain a /tʃ/ (the CH of church) that surprises learners who expect a plain /ʃ/.

Why It Happens

In nation, the T + I + ON sequence turns the T into /ʃ/. But when an S sits right before that T, the cluster ST + I + ON behaves differently: the S stays /s/, and the T + yod blend into /tʃ/ (the same process that turns got you into "gotcha"). The result is /s/ + /tʃ/ + /ən/ = /s.tʃən/. You can hear the S and the CH as two separate pieces: "s-chun."

-TION vs -SION vs -STION

The Full Word List

The -stion pattern is small and consistent, so you can simply learn the members:

• question /ˈkwɛstʃən/
• suggestion /səˈdʒɛstʃən/
• digestion /daɪˈdʒɛstʃən/ and indigestion /ˌɪndaɪˈdʒɛstʃən/
• congestion /kənˈdʒɛstʃən/
• combustion /kəmˈbʌstʃən/
• exhaustion /ɪɡˈzɔːstʃən/
• bastion /ˈbæstʃən/

The Related -STIAL Pattern

The same ST + yod blend appears in the ending -stial, which becomes /stʃəl/:

Common Mistakes

1. Saying 'KWES-shun' (losing the T)

If you drop the /t/, question turns into "kwesshun." Keep the crisp CH: "KWES-chun." The T is not silent, it has fused into the CH.

2. Saying 'KWES-tee-on' (spelling pronunciation)

Do not pronounce each letter as "kwes-ti-on." The -TION is never two syllables here; it is the single /tʃən/.

3. Forgetting the voiced G in suggestion

In suggestion, digestion, congestion, the G before -estion is /dʒ/ (the J of jam): "suh-JES-chun," "dy-JES-chun." Keep that J and then the CH ending.

Practice Sentences

• I have a quick question about your suggestion.
• Heavy meals slow down digestion and can cause indigestion.
• Traffic congestion led to total exhaustion.
• The engine relies on internal combustion.

Quick Reference

Keep Going

The CH sound that hides in -stion is the same /tʃ/ you can practise across the site. Sharpen it with the word pronunciation practice and browse more rules on the pronunciation blog.