If illative ends with -sesse, then the short form is -sse.

The paradigm usually consists of the inessive, elative and illative cases.

While all nouns have a regular ending for the six locative cases, many have a preferred irregular short illative form.

The Illative sense is for Newman, the intellectual counterpart of Aristotle's Phronesis.

Illative case ("into")

The illative case can vary between -э/-е and -ы.

In older Lithuanian texts three additional varieties of the locative case are found: illative, adessive and allative.

The illative case, denoting direction of movement, occurs rarely in modern standard Lithuanian, although used in the common spoken language, especially in certain dialects.

The illative case in Lithuanian has its own endings, that are different for each declension paradigm, although quite regular, compared with some other Lithuanian cases.

Similar changes affected the illative ending, which was -hVn where V was the same as the vowel preceding the ending.

The Estonian illative case, for example, is expressed by a modified root: maja majja (historical form *majam).

The illative case also changes form with a consonant stem, where the ending -hen is assibilated to -seen, as -hen is the genitive.

For example, an inessive case, an illative case, an adessive case and allative case are borrowed from Finnic.

It is done in loanwords and abbreviations; e.g., USA:han for the illative case of "USA".

Thus, applying the illative suffix -Vn to a word 'kukka' 'flower' should result in '*kukaan', however the word actually surfaces as 'kukkaan'.

One such example is found in the illative singular of nouns, e.g. kukka 'flower' kukkaan 'flower+Illative'.

One epenthetic vowel is the preceding vowel, found in the illative case ending -(h)*n, e.g. maahan, taloon.

The illative marker is -j in the singular and -da in the plural, which is preceded by the plural marker -i, making it look the same as the plural accusative.

In the study of illative combinatory logic, Curry in 1941 recognized the implication of the paradox as implying that, without restrictions, the following properties of a combinatory logic are incompatible:

The original locative case had been replaced by four so-called postpositive cases, the inessive case, illative case, adessive case and allative case, which correspond to the prepositions "in", "into", "at" and "towards", respectively.

Another etymology is the vocalization of a fricative such as the voiced velar fricative or voiced palatal fricative, e.g. Finnish illative case, or even an approximant, as the English 'r'.

The illative case was used extensively in older Lithuanian; the first Lithuanian grammar book by Daniel Klein, that mentions both illative and į+accusative, calls the usage of the illative "more elegant".

Between two unstressed short vowels (i.e. in the weak grade of suffixal gradation), *ð and *h were lost (but not after a diphthong, cf. illative plurals in -oihin, verbs in -oida); these may be preserved in a variety of dialects.

In modern Finnish, it has been superseded by a more complicated system of locative cases and enclitics, when the original -s has merged with another lative or locative suffix, and turned into the modern inessive, elative, illative and even translative suffixes.

Singular illative has a short form in some words.

The illative of the third infinitive is a common inchoative, governed by such verbs as ruveta and joutua:

Instead of adding an sse suffix to the genitive, the short illative is pronounced in an overlong manner, reflecting phonetic gemination and a shift from the second to third phoneme length, without adding an extra syllable.