Suffix · forms nouns
Variant of -tion that turns verbs into nouns: decide becomes decision.
Written by Bryan López, English teacher · Updated
The suffix -sion is a variant of -tion: both turn verbs into nouns. The difference is in spelling and pronunciation. From "decide" comes "decision"; from "extend" comes "extension"; from "permit" comes "permission". The choice between -tion and -sion is not free: it depends on the base verb and its Latin origin. It is learned word by word, not with a single rule.
-sion can sound two different ways: /ʒən/ = "zhun" (like the French "j"): when it follows a vowel or l/r/n. decision = de-CI-zhun, television = tel-e-VI-zhun, version = VER-zhun. /ʃən/ = "shun": when it follows a voiceless consonant. passion = PA-shun, mission = MI-shun, tension = TEN-shun. The difference between /ʒ/ and /ʃ/ can be subtle. Practise by listening to both groups.
The match with Spanish is direct: decision = decisión extension = extensión tension = tensión television = televisión version = versión If a Spanish word ends in -sión, the English version almost always ends in -sion.
Verbal root + sion. The choice between -tion and -sion depends on the verb.
A practical hint: if the base verb ends in -d, -de, -se or -mit, the noun probably uses -sion. If it ends in -t or -te, it usually takes -tion. But there are exceptions — learn the most common words directly.
-sion/ʒən/ or /ʃən/ · sounds like 'zhun' or 'shun'
Tap the button to hear how the ending sounds. Each word in the table has its own audio.
decide → decision (not "decition" or "decidion"). The suffix is -sion, not -tion or -dion.
extend → extension (not "extention"). Even though the verb ends in -d, the noun uses -sion.
permit → permission (double -ss-). Not "permition" or "permision" (one s).
A trick to remember it
If the verb ends in -de, -d or -mit, the noun probably uses -sion: decide → decision, extend → extension, permit → permission. And remember: -sion sounds "zhun" in decision/television and "shun" in mission/passion.
Exercise 1 · Form the word
Exercise 2 · Pick the right one
How is the -sion pronounced in "television"?
Exercise 3 · Pick the right one
"permission" in Spanish is...
The suffix -sion variant of -tion that turns verbs into nouns: decide becomes decision. In Spanish it usually maps to -sión / -ción.
The ending -sion is pronounced /ʒən/ or /ʃən/ · sounds like 'zhun' or 'shun'. For example, "decision".
"decide" becomes "decision". It is a typical example of the -sion suffix.
Turns a verb or adjective into the noun naming that state or quality: import becomes importance.
Turns a verb into the noun that names the action, process or its result: develop becomes development.
Turns verbs into nouns that name an action or its result: educate becomes education.
-tion, -ness, -ful, -ly, -able... every ending you need to understand thousands of words at once.