In linking a subordinate clause and a main clause, a relative pronoun functions similarly to a subordinating conjunction. Unlike a conjunction, however, a relative pronoun does not simply mark the subordinate (relative) clause, but also plays the role of a noun within that clause.
The main ingredient in most vodkas is some kind of grain, such as wheat, corn or rye. Potatoes are another common base ingredient for vodka, according to About.com.
Vodka is most commonly made from fermented grains or potatoes, but some vodka originates from grapes or sugarcane. Availability. This is the general availability within the United States, to estimate availability we search common online and in shop retailers to judge the commonality of each bottle.