In linguistics, morphological leveling or paradigm leveling is the generalization of an inflection across a linguistic paradigm, a group of forms with the same stem in which each form corresponds in usage to different syntactic environments,[1] or between words.
An example is the conjugation of English verbs, which has become almost unchanging today (see also null morpheme), thus contrasting sharply, for example, with Latin, in which one verb has dozens of forms, each one expressing a different tense, aspect, mood, voice, person, and number.
[4] In trans-paradigmatic leveling, the process occurs between two forms originating from two separate paradigms.
To be leveling is considered the extension by analogy[5][6][7] of the (more frequent) third-person singular form is to other persons, such as I is and they is.
An ablaut is the vowel changes within a single root or its relations that is common to many Indo-European languages.
[10] In more general terms of Appalachian English, speakers will use the past tense form of to be instead of using the other conjugations of the verb.
The original strong forms of these and most other leveled verbs are readily understood by modern English speakers but are seldom used.
For example, the word he'd in Australian English has experienced an internal leveling in terms of vowels.
An example of this would be the verb meaning to write, which is conjugated below: The vowels for the preterite singular and past participle are "e" and "i", respectively.
German and Dutch follow a different pattern, in that the vowels of the preterite singular and past participle are kept the same.
In the chart above, both the Dutch and German versions of the verb to offer keep the vowel of the preterite singular the same as the past participle.