amazed

amazed + at + noun
I was amazed at his recovery.

amazed + by + noun
I was amazed by his recovery.

amazed + clause
I am amazed he won first prize.

amazed + that + clause
I am amazed that he won first prize.

amazed + how + clause
I am amazed how easy he won the competition.

amazed + at + how + clause
I am amazed at how easy he won the competition.

adverb + amazed
I am totally amazed at how easy he won the competition.