What is the force of prefixes on perfective and imperfective verbs? Are all prefixed verbs perfective?

Question

So you have the perfective and imperfective form of verbs, e.g. дарить и подарить. This is sometimes determined by the prefix, as shown above. But verbs can also have other prefixes which determine meaning (I’ll refer to these as special “prefix meanings”, as I don't know what else to call them), e.g. ходить и уходить.

So, does this mean that only the perfective form of the verb can have a special “prefix meaning”, or does it just mean that verbs for which the prefix changes for the perfective (first example) cannot have a special “prefix meaning”. Is it possible for imperfective verbs to have a "prefix meaning"? or would giving an imperfect verb a prefix automatically make it a perfective verb?

Answer 1

In terms of non-verbs of motion, a meaningful prefix such as о- (about, around) can be added to the stem -ПИС- (write), for example, to convey the meaning of describing. Without this prefix, that meaning is lost, so both the perfective and imperfective have to have it. Russian resolves this by means of an infix for the imperfective: о-пис-áть (perfective) and о-пи́с-ыв-ать (imperfective) to describe.

Verbs of motion play by different rules in Russian. Unprefixed verbs of motion have two imperfective forms (unidirectional идти and multidirectional ходить) and normally form the perfective by means of the prefix по- added to the unidirectional (пойти). However, once a directional prefix is added to a verb of motion, it acts just like any other verb with one imperfective form (уходить) and one perfective (уйти).

Answer 2

There is, of course, a correlation between the aspects and prefixes. Prefixes are usually used to form perfectives from imperfective verb forms. But there are so many exceptions that it's easy to get frustrated.

Consider the verbs of movement that you mentioned:

идти
ходить

How easy would it be to derive prefixed imperfective derivatives from these two? (To contradict the rule).

проходить
переходить
выходить
сходить

And I cannot think of any prefixed form of идти, which is also imperfective.

So I wouldn't rely on prefixes when trying to form perfectives. Prefixes can give you a semantic and aspectual hint, but the actual meaning is often semantic, not grammatical.