In the present indicative singular, many of the classes exhibit a change in the stem vowel ( in this case, e-> i ).
12.
For example, the common initial reduplication process, which copies the first stem vowel, copies only the first member of a diphthong, e . g .:
13.
In Greek, some of the Latin conjugations are represented by contracted verbs instead, in which the stem vowel contracts with the ending ( which includes the thematic vowel ).
14.
Most irregular nouns take an ablaut plural ( with a change in the stem vowel ), or combine ablaut stem-change with the suffix, and some have unique plural forms.
15.
While all verbs in the aorist ( except " AC < " ) take the same endings, there are complexities in the aorist stem vowel and possible consonant alternations.
16.
The first class of consonant-stem words largely resemble " e "-stems, but allow elision of the stem vowel in the partitive singular, and for certain words, plural genitive.
17.
Strong verbs, by contrast, form their past tense by changing their stem vowel ( " binden " becomes " bound ", a process called apophony ), as in Modern English.
18.
Modern Lithuanian grammarians no longer consider the 3rd person as having an ending, instead it is now called the " final stem vowel " to which a personal ending is attached in order to make the 1st and the 2nd persons:
19.
However, for a few verbs, for instance i-a-u verbs, change the stem vowel to u before appending an-e to the past tense indicative form . ( Any final deponent-s is unaffected .)
20.
Not all verbs with a change in the stem vowel are strong verbs, however; they may also be irregular weak verbs such as " bring, brought, brought " or " keep, kept, kept ".
