Rewrite the sentence.

[hoangkha]

Hi!
How inconsiderate he was to take your book! (thoughtless)
1- How thoughtless he was to take your book!
2- What a thoughtless man he was to take your book!
Is the second all right, please?

 

[meskete]

It sounds all right to me.
Let me recommend another version: How thoughtless of him to take / have taken your book!

 

[Raymott]

It sounds all right to me.
Let me recommend another version: How thoughtless of him to take / have taken your book!

Yes, and if you want a full sentence (with a finite verb) you can say:
"How thoughtless it was of him to take your book!"

 

[hoangkha]

OK.
or
- How thoughtless of him it was to take your book! All right?

 

[Raymott]

OK.
or
- How thoughtless of him it was to take your book! All right?

Yes.