Question

Which sentence uses the correct form of interesting to make a comparison?

That's the most interestingest book I've ever read.

That's the most interesting book I've ever read.

That's the interestingest book I've ever read.

That's the more interesting book I've ever read.

Answer 1

That's the most interesting book I've ever read. (second option)

Step-by-step explanation:

The sentence requires the superlative degree of the adjective describing the noun 'book'.

The adjective interesting forms its superlative degree by placing 'most' before the positive form: the most interesting.

Answer 2

the others doesnt make sense if you re read them so it would be the second one