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
| Ending | Sound | Examples |
|---|---|---|
| -tion | /ʃən/ "shun" | nation, station, education, attention |
| -sion (after vowel) | /ʒən/ "zhun" | vision, decision, confusion, television |
| -sion (after consonant) | /ʃən/ "shun" | tension, mansion, expansion, pension |
| -stion | /s.tʃən/ "s-chun" | question, suggestion, digestion, combustion |
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
| Word | IPA | Say it as |
|---|---|---|
| question | /ˈkwɛstʃən/ | KWES-chun |
| suggestion | /səˈdʒɛstʃən/ | suh-JES-chun |
| digestion | /daɪˈdʒɛstʃən/ | dy-JES-chun |
| combustion | /kəmˈbʌstʃən/ | kum-BUS-chun |
| celestial | /səˈlɛstʃəl/ | suh-LES-chul |
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.