What are the differences between amazing and amaze?

[Luke_Wanttolearn]

English Grammar Tests, Elementary Level

ESL/EFL Test #57 "Chit Chat: At the pub", question 7

Charles: That's really ......... I find that difficult to believe.

(a) amaze
(b) amazing
(c) amazes
(d) amazed

English Grammar Tests, Elementary Level

ESL/EFL Test #57 "Chit Chat: At the pub", answer 7

Charles: That's really amazing I find that difficult to believe.

Correct answer: (b) amazing
_________________________

What are the differences between amazing and amaze in this case, sir?

[Mister Micawber]

.
Here, an adjective is required: That is ... amazing. Amaze is a verb and does not fit the grammar of the sentence.
.
_________________
Native English teacher at Mister Micawber's