I've noticed that some imperfective verbs are converted to the perfective by just adding a prefix. However and oddly enough, sometimes there's an alternate imperfective formed from an internal modification of the prefixed verb itself!
I'm not taking into account verbs in which the prefix conveys a different meaning rather than just changing the verb aspect.
For example, делать
, meaning "to do", is imperfective; if we add the prefix под, the word becomes подделать
, which is perfective and means "to falsify". If we want to change the new verb to imperfective once again, then an internal modification is required, and thus it becomes подделывать
.
Now to the point: the verb цвести ("to flourish") is imperfective and its perfective counterpart is расцвести. However, it seems that расцвести
accepts two imperfectives: both the "original", unprefixed цвести
, and a variation from the prefixed verb itself: расцветать.
The same goes for растянуть, which, apparently, accepts both тянуть and растягивать as imperfectives.
However, is there any difference in meaning, or are both imperfectives interchangeable?