-іння

• -ї́ння (-jínnja)

Inherited from Proto-Slavic *-nьje. Reanalyzable as -ін (-in) +‎ -ня (-nja), -і (-i) +‎ -ння (-nnja)

• -і́ння: IPA^(key): [ ˈinʲːɐ]
• -іння: IPA^(key): [ inʲːɐ]

-і́ння or -іння • (-ínnja or -innja) n (plural -іння, variant -ення)

1. -tion, -ence, -ance, -ity, etc. (suffix used to form abstract nouns from verbs, and occasionally from other parts of speech)

   ‎вмі́ти (vmíty, “to be able”) + ‎-і́ння (-ínnja) → ‎вмі́ння (vmínnja, “ability”)

• The stress is usually drawn onto the suffix, but occasionally not.
• This suffix is generally used only for verbs whose past passive participle ends in -єний (-jenyj) or -ений (-enyj); verbs whose past passive participle ends in -аний (-anyj) normally use -ання (-annja), and verbs whose past passive participle ends in -тий (-tyj) normally use -ння (-nnja).
• The stem preceding the suffix is modified in the same way as for the past passive participle; in particular, the stem normally becomes iotated, and in cases where the stem iotates irregularly in the past passive participle (e.g. -жд- (-žd-) instead of -ж- (-ž-), or -щ- (-šč-) instead of -ч- (-č-)), the same irregularities are observed before -і́ння (-ínnja).
• Note that even intransitive verbs without a past passive participle form abstract nouns in -і́ння (-ínnja). For such verbs of class 4 and 5 (which end in -ити (-yty) and -іти (-ity) respectively), use the stem as found in the first person singular.

• -ення (-ennja), -ання (-annja), * -ння (-nnja)