There are several types of valency: impersonal (=avalent), intransitive (=monovalent), transitive (=divalent) and ditransitive (=trivalent):an impersonal verb takes no arguments, e.g. It rains. (Though it is technically the subject of the verb in English, it is only a dummy subject, that is a syntactic placeholder - it has no concrete referent. No other subject can replace it. In many other languages, there would be no subject at all. In Spanish, for example, It is raining could be expressed as simply llueve.)an intransitive verb takes one argument, e.g. He1 sleeps.a transitive verb takes two, e.g. He1 kicked the ball2.a ditransitive verb takes three, e.g. He1 gave her2 a flower3.