The insertion of an "-a" or "-i" suffix between "-tion" and the preceding syllable is a consequence of two things: The relative emphasis of the preceding syllable (is it lightly emphasized, strongly emphasized, or de-emphasized?) and the final consonant/vowel array.
suffixes - Word formation with the nominal suffix -tion: when and why ...
Italian: rela zione, astra zione, conges tione Of course, the "rule" I outlined does not apply to all words that just end in the letters "tion" in English: the most notable counterexample is the word cation. However, I can't think of any counterexamples to my rule when dealing with the actual suffix -tion.
What are the rules to pronounce the suffix "-tion" in English, "/-tʃən ...
The suffix tion is pronounced as /ʃən/ (shun) and not /tʃən/ (chun). According to an answer by user Kosmonaut to a question "What rules of English allow the first t in “patient” to make an sh sound?": The reason something pronounced [ʃ] ("sh") would ever get the spelling "ti" is because of palatalization.
We noticed that before the suffix -tion, the "i" is always a short sound, despite being an open syllable. All the other vowels are mostly pronounced as long sounds, as expected in open syllables.
Why is "i" before a -tion suffix pronounced like a short vowel even ...
It looks like it is an exception from the more common -tion -sion spellings, retaining the original French spelling. -tion syllable formed when the word-forming element -ion (from Latin -io) is fixed to a base or to another suffix ending in -t or -te. In Middle English, in words via Old French, it often was -cion (in coercion and suspicion, however, the -c- belongs to the base). -cion It ...