The sentence with the correct word completing it is: "I have the <em>shortest</em> fingers of enyone in my family." This is the <em>superlative form</em> for short adjectives: <em>the + adjective + est </em>= the shortest (the longest, the hottest, the easiest etc). For longer adjectives, the superlative form is: <em>the most</em> + <em>adjective</em> ( the most enjoyable; the most beautiful etc).