I was doing a quiz on this webpage http ://www.usingenglish.com/quizzes/answers.php?quiz_id=80 .There was a quiz asking whether the structure 1. ( very+adjective+infinite) is true or false.My answer was true but i got it wrong.But on the other hand I got another quiz 2. (it was very expensive to buy it) on the same quiz page.So according to the last quiz,my answer that I provided for the first quiz must be correct.I am confused about it.Please give me an accurate solution.
I can understand your confusion.
I think you are referring to Q9 and Q12 here.
I personally do not agree with the answer to Q12. The answer is 'True' in my opinion.
Let's wait for some native speakers to respond.
(Edit) If the question is intended to mean "We can use the structure - very + adjective + infinitive without to", then the answer would be 'False'.
"very + adjective + to-infinitive" is OK, as in
I'm very happy to know you'll come back.