And there are two ways of expressing single complete(d) past actions: the aorist,
and the perfect formed with the perfective l-participle:
(52a) Blg pop ˘atu
´
vax [Aor] ‘I went’
(52b) Blg pop ˘atu
´
val s ˘am [Perf Prfv] ‘I went’
This overlap is commonly supposed to have brought about the development of the
B system, which eliminated the imperfect and aorist in favor of the l-participle
forms. We can even see this process at work in modern B/C/S, where the imperfect
and the aorist have been almost totally replaced in the spoken language by the
forms with the l-participle, and are optional even in the literary language (Browne,
1993: 330).
The result of this reorganization of the tense system can be expressed in another
way. In the A system the verbs are organized very much around the tenses; aspect
is operative, but only as one component of verb forms. But in the B system aspect
has become much more prominent, particularly in the past tenses. Both aspect and
tense are present in both the A and B systems, just as they are in English. But in
the new B system there has been a certain shift which has given aspect a more
obvious, often dominant, role.
5.4.7 Aspect
Since aspect is discussed in some detail in 6.3 and 8.3, we restrict ourselves here to a
basic overview of the issue. There are two aspects: perfective and imperfective,
which are not to be confused with the perfect and imperfect tenses (5.4.6). As a first
approximation, perfective verb forms express an action or state which is seen as
complete, completed, total, or unified, or with reference to a specific location in
space and time, or to the completion of a specific goal (‘‘telic’’). The imperfective
expresses actions or states which are incomplete, still in progress, repeated or
habitual (6.3, examples 114–115).
The present tense is therefore normally imperfective (except in a few instances,
especially in B/C/S and Czech, see 6.3, examples 117, 200). Past and future tenses,
as well as the participles, gerunds and imperatives, can be either perfective or
imperfective. Past perfectives share inflexions with past imperfectives, and future
perfectives share inflexions with the present (6.3, examples 118–119).
Differences in aspect are signalled by the verb stem, where word-forming processes
are used to construct perfective stems from imperfective stems (mainly by pre-
fixation), and imperfective stems from perfective stems (mainly by suffixation)
(see 8.3). Aspect therefore belongs partly with inflexional morphology, and partly
with word formation (8.3). We discuss aspect as a morphosyntactic category in 6.3.
244 5. Morphology: inflexion