Quote Originally Posted by Yuki View Post
Can I use the above sentence : "1) Я могу предлагать интересные идеи." for one time only ( not generally )?
Normally not.

Can I say "Я сейчас могу предлагать интересные идеи." ?
You can, but in this sentence "сейчас" means "nowadays" or "in this period of my life" rather than "right now".

Suppose both sentences are used in reply to Кто может предложить свои идеи?
The second sentence is preferable. The first will need further explanations.

Imperfective verbs can describe either multiple actions (iterative) or the very process of doing something (progressive), while perfective verbs are used for one-time accomplished actions.