As stated up there in my comment, Heatran is an ideal counter to Clefable. Standard Clefable sets have nothing to hit it. All you really need to do is keep it relatively healthy and you can stop Clefable easily. I suggest Heatran over other Steel types, and there is two reasons for this. The first is its Fire immunity, as most good Clefable sets run Flamethrower.
Definition. The genitive is the case (or function) of an inflected form of a noun or pronoun showing ownership, measurement, association, or source. Adjective: genitival. The suffix -'s on nouns is a marker of genitive case in English.
The nominative case of a noun is used whenever the noun is the subject of the sentence. For example, in The farmer was happy, the farmer would be written as a nominative singular noun because it is the subject of the sentence. The genitive case of a noun is used whenever the noun becomes possessive.