Can intransitive verbs be converted into transitive verbs?

There is no regular process in English for converting intransitive verbs to transitive, but it can often be done.

Two examples of verbs which, as far as I can think, can never take a direct object are exist and dine. But sleep (which you might think was archetypically intransitive) has a transitive meaning "accomodate for sleeping", as in This cabin sleeps eight people.

Then there's the vexed question of whether sentences like "He died a good death"; "They slept the sleep of the blessed" and "It's raining cats and dogs" should be analysed as transitive or not. Syntactically they are indistinguishable from transitive sentences, but the NP after the verb is not usually regarded as an object.