Grammar

I was puzzled by this sentence on the BBC Russian Service:

Нет свидетельств тому, что на нынешних выборах дело обстоит иначе.

It means “There is no evidence that in the current election things are any different.” but the puzzle isn’t the meaning, it’s the grammatical case in which the author has placed the demonstrative pronoun то , which is dative here тому . The thing is that you see examples where either the genitive or the dative follows свидетельство . So what’s the difference?

Semelfactive verbs, a special class of perfectives. (Applies to Russian, but also to English grammar, too.)

A pervasive, but unusual feature of Russian grammar.