The correct form is "Fred is less tall THAN the two boys". Use "than" and NOT "of" when comparing. Although grammatically it is correct, it is common to use expressions as the following: "Fred is not as tall as the two boys" or better "Fred is shorter than the two boys" If you want to underline that Fred is the "shortest" then the correct from would be: "Fred is the shortest between the two boys"

First of all it should be: of THE two boys - this information us about a specific set of boys In the same way you should use "the less tall" taller= "more" tall Does this help?

None of them are correct. Fred is the smaller of two boys. This is only used when talking about somebody else's children. If Jack has two boys (sons) then you can say: "Jimmy is the smaller of two boys." Otherwise the sentence doesn't make sense.

Sure! A is shorter than B. C is shorter than A. C is the shortest. B is the tallest. "the shortest" is superlative between more than two nouns. It describes the highest degree, quality or order of the adjective. If there are more than two syllables we usually say "the most..." For example, "Alice is the most beautiful princess of all" "shorter than" is comparative between two nouns "Shrek is more charming than Prince Charming."

Yes, I was wrong...they are now three :D...sorry... Can you please explain why "the shorter" and not "the shortest"??